officer’s facetious comment is in fact absolutely true. This scene also contains dramatic irony, which refers to a situation in which the audience knows something that certain characters do not know. The audience is well aware that having bludgeoned her husband to death with the leg of lamb, Mrs. Maloney has carefully prepared it for dinner and is calmly watching the police consume the evidence.

Previously, when Mrs. Maloney is conversing with the grocer, a further example of dramatic irony takes place, because the audience is aware—while Sam is not—that there is certainly no need to be discussing what Mr. Maloney will be having for dessert.

An earlier example of verbal irony can be found in the aftermath of Mr. Maloney announcing his news. Moments before the leg of lamb hits the back of his head, he informs his wife that he is going out. As it turns out, he’s certainly going “out” but not to whatever destination he had been imagining.

Irony can be:

• Situational: actions result in a different outcome than expected
• Verbal: sarcasm; when words mean the opposite of what they originally intend to mean
• Dramatic: actions and events understood by the audience, but not the characters

All three examples of irony are evident in "Lamb to the Slaughter."

The verbal irony is found in the title of the story. The phrase "Lamb to the Slaughter" suggests an innocent creature about to undergo torture and death. Mary Maloney could represent such a creature, and she would have met a similar fate if she had been found guilty of killing her husband.

More verbal and situational irony is represented in the murder weapon and what happens to it, unbeknownst to the people investigating the scene of the crime.

The murder weapon is a frozen leg of lamb. Mary hits her husband with it after mentally "snapping" when he announces to her that he will leave her. The hit kills him instantly. Shortly after, Mary comes up with a way to dispose of the murder weapon: she cooks it. What's more, she feeds it to the policemen who come to investigate the scene.

As the audience, we know what is going on.The characters do not. That would be the dramatic irony. We realize that they are eating the very thing they need to find in order to apprehend the person guilty of killing their fellow policeman, Patrick Maloney. They even comment that the murder weapon could be right "under their noses," which it is.  

Meanwhile, in the other room, Mary Maloney giggles at the situational irony of it all. The lamb, after all, saved her from the slaughter of what could have been a death sentence, or life in jail as a pregnant woman.

Situational irony occurs when something that happens is the opposite of what we would normally expect to happen or find appropriate. Certainly, the major piece of situational irony is found when Mary Maloney, who Dahl goes to great lengths to depict as a loving wife who is devoted to her husband, in a moment of madness, kills him. Consider how she is introduced:

For her, this was always a blissful time of day... She loved to luxuriate in the presence of this man, and to feel - almost as a sunbather feels the sun - that warm male glow that came out of him to her when they were alone together.

Mary Maloney is presented as being so obsessed with her husband that nothing is too much to ensure his comfort and happiness. Then it is a complete shock to us as readers when she kills him with the frozen leg of lamb:

At that point, Mary Maloney simply walked up behind him and without any pause she swung the big frozen leg of lamb high in the air and brought it down as hard as she could on the back of his head.

This action is completely the opposite of what we would expect a character like Mary to be able to do. The second piece of situational irony comes when she manages to very coolly and in a calculating fashion organise an alibi and the removal of the murder weapon. Consider the last line, where Mary celebrates the success of her plan:

And in the other room, Mary Maloney began to giggle.

Again, this criminal behaviour and outwitting of the policemen is not the kind of activity we would expect to see from a devoted housewife. Both of these incidents serve to shock us in the story through the use of situational irony.

One example of verbal irony in the story occurs just before Mary learns that Patrick is leaving her.  When discussing dinner options, she says, "There’s plenty of meat and stuff in the freezer, and you can have it right here and not even move out of the chair."  Looking back, this is ironic because Mary does in fact bring the leg of lamb into the living room.  Patrick "has" the lamb, but certainly not in the same way that Mary intended when she said this to him earlier in the story. 

Another example of verbal irony occurs later in the story after Patrick is already dead.  Mary has put on a little show for the grocer and she goes back into the house and calls to her husband, "How are you, darling?"  She obviously knows that he is dead, so her asking how he is doing is quite ironic.

Dramatic irony occurs when the audience has knowledge of something that some or all of the characters do not, and because of that words or actions have a different meaning.  In "Lamb to the Slaughter" the reader knows that Mary Maloney, having been told by her policeman husband that he is leaving her, has killed him with a frozen leg of lamb.  The dramatic irony occurs when she cooks the lamb and serves it to the men investigating her husband's death while they speculate about what the murder weapon might have been and where is could be.  In fact, one of them remarks the evidence they are seeking is probably "right under their noses." The reader knows they are eating the very weapon they are seeking!  That is dramatic irony.

Another example is the very last line of dialogue in the story.  The officers are consuming the leg of lamp and discussing the murder while, obviously, digesting the murder weapon.  Then one officer states that the weapon is "probably right  under our very noses."  And, of course, it is.

There are a couple of ironic points to this story. First of all, the title is a pun. A lamb to the slaughter usually refers to someone who is unaware they are about to be harmed, since lambs are easily led to their slaughter since they trust the one leading them and they are unaware of what is to become of them.

In this story, the husband, Patrick Maloney, is killed like a lamb, totally trusts his wife Mary and is completely unaware of his impending doom, but the title is also ironic because it is actually a frozen leg of lamb that is used to slaughter the hapless victim.

The final irony is dramatic irony, because the reader knows that the leg of lamb was used as a murder weapon, but the police unwittingly eat the evidence when the killer serves the roast leg of lamb to them.

There are many examples of irony in Dahl's “Lamb to the Slaughter.” The central irony is that an ostensibly meek and mild housewife turns into a murderer—one who outsmarts the police and expertly covers her tracks.

At the end of the story, we are treated to a further irony, this time a prime example of what's called dramatic irony. This is where we know something that some of the characters don't. In this particular case, we know that the leg of lamb that Mary's serving up to the police officers investigating her husband's death is the murder weapon. But the police officers remain blissfully unaware of this, hence the dramatic irony.

One irony has led to another. No one would think Mary capable of even harming a fly, and yet she has murdered her husband and covered her tracks like a pro. This leads directly to the story's final irony, in which police officers investigating her husband's murder unwittingly eat the evidence of Mary's crime. Without this evidence, it's highly likely that Mary will get away with murder. And irony of ironies, the police, albeit inadvertently, have helped her do it. Knowing all this, Mary can't help but let out a giggle at the story's end.

The title of Roald Dahl's story is ironic in a couple of ways. Lambs are symbolic of innocence, and though Mary Maloney's husband is slaughtered (with a leg of lamb, no less), he is far from innocent. He has, assumedly, been planning to desert his pregnant wife and announces his intention with no compassion. Mary can be read as the innocent—so perhaps she is the lamb who has been driven to slaughter, which subverts the usual reading of the titular phrase.

That the leg of lamb becomes the murder weapon is also ironic. Lamb is noted for its tenderness, and what should be the foundation of a comforting meal shared by a loving couple becomes the agent of Patrick's destruction. Compounding the irony is that the police who come to investigate unwittingly consume the physical evidence of their fallen colleague's murder.

The irony in the title of Roald Dahl's story "Lamb to the Slaughter" has to do with the tension between the literal and figurative meanings of the phrase in the title.  At the beginning of the story, the main character Mary Maloney is trying to put together dinner for her husband Patrick.  She tells him that she has taken out a leg of lamb for dinner, but he does not really care.  Shortly after, Patrick tells Mary that he is leaving her.  By this point it is obvious that there have been problems in the marriage, and Mary clubs Patrick over the head with the leg of lamb--so she literally "slaughters" him with the lamb.  However, figuratively, the phrase alludes to the loss of innocence that occurs when people reach certain stages of life.  The lamb has been used throughout literary history to represent innocence and the slaughter to represent the moment when that is lost.  Mary suggests that her husband has not been the best partner for her, so it is also ironic that he decides to leave her.  Mary loses her innocence when she takes his life and has to then try to cover up her crime and atone for her actions.

Situation irony occurs when events in a story work out in an unexpected way, usually the opposite of what we would expect.

"Lamb to the Slaughter" is filled with situational irony. First, given how Mary looks forward to her husband's return from work, how devoted to him she is, and the fact that she is pregnant, the last words we would expect from him are that he is going to divorce her. It is also ironic that he expects her to take this news calmly and rationally given the level of devotion and attachment she has shown to him.

It is ironic as well that a woman who seems so sweet, domestic, and innocent would whack her husband over the head with a frozen lamb chop and kill him.

Finally, it is ironic that Mary feeds the police officers who come to investigate her husband's death the murder weapon. Just as we do not expect Mary, who seems so docile, to kill her husband, we also don't expect her to have the brains and nerves to so cleverly get rid of the evidence of the crime.