How many times does the word "Mockingbird" appear in the book To Kill a Mockingbird?
The word "mockingbird" is not actually used all that many times in the novel. I believe it is first mentioned in Chapter 10 when Scout reflects about why Atticus wouldn't teach his kids to shoot the air-rifles given as presents by their Uncle Jack. Atticus reminded them "to shoot all the blue jays you want... but remember, it's a sin to kill a mockingbird." Because it was the only time that Atticus had ever said it was a sin to do something, Scout decided to ask Miss Maudie about it. She explained that
"... Mockingbirds don't do one thing but make music for us to enjoy. They don't eat up people's gardens, don't nest in corncribs. They don't do one thing but sing their hearts out for us. That's why it's a sin to kill a mockingbird."
Much later, after Scout has survived the attack by Bob Ewell, she tells Atticus that "Mr. Tate was right" about not wanting to bring charges against Boo Radley. Atticus asked what she meant.
"Well, it'd be sort of like shootin' a mockingbird, wouldn't it?"
So, the word "mockingbird" is used at least four times in the novel.