A literary device is a device used in writing to convey some kind of imaginative effect. Even the title uses the literary device of repetition in order to engage the reader.
Line one greets us with onomatopoeia and personification.
The buzz-saw snarled and rattled in the yard (line 1)
Frost uses onomatopoeia in the words “buzz” and “rattled” to bring sounds of the farm into the poem. He also personifies the saw by saying it “snarled” as an angry person (or animal) might. This seems to give the saw a personality, and foreshadow danger. The words “snarled and rattled” are also repeated twice in line 7.
The saw is also personified again when the saw leaps toward the boy’s hand when his sister distracts him.
At the word, the saw,
As if to prove saws knew what supper meant,
Leaped out at the boy's hand, or seemed to leap—
He must have given the hand. (lines 14-16)
A simile and metaphor are also used to describe the boy’s reaction to losing his hand.
The boy's first outcry was a rueful laugh,
As he swung toward them holding up the hand
Half in appeal, but half as if to keep
The life from spilling. (lines 18-21)
The words “as if” mark the simile, and the metaphor is the life spilling out of his hand, which is literally the blood spilling.
In this poem Robert Frost uses literary devices including allusion, imagery, foreshadowing, irony, and understatement.
An allusion is a brief reference to a historical event or literary work that brings an associated meaning. The title, "Out, Out--," is a reference to Shakespeare's Macbeth. When Macbeth mourns Lady Macbeth's death, he laments, "Out, out, brief candle!" Before her death, Lady Macbeth, mad with guilt, mutters, "Out, damned spot! out, I say!" Both references apply here. The boy who dies in the accident dies too early--the candle of his life has been too brief. But the adults, who gave the boy a man's job to do, must live with the guilt all their lives of wishing they had prevented the fatal accident.
Imagery is a device that allows readers to experience a scene with their five senses. The sounds of the buzz saw ("snarled and rattled"), the description of the setting ("Five mountain ranges one behind the other/ Under the sunset"), the boy's rueful laugh, and the way he holds up his severed hand are all vivid images that bring readers into the poem.
Foreshadowing predicts what will happen later. When the poet speaks in first person, "Call it a day, I wish they might have said," readers know something unfortunate is going to happen.
Irony is when the opposite of what is expected happens. The boy's "rueful laugh" is ironic because laughter is out of place in such a tragedy. Even the statement that "he saw all spoiled" turns out to be ironic. The boy thought he was facing only amputation, which as it turned out, would have been a preferred, even blessed, outcome compared to the boy's death.
Understatement occurs when words are used that minimize the emotions or import of an event. The ending of the poem is shocking in its lack of emotion and proper tribute to the dead boy and those who witnessed the tragedy:
"No more to build on there. And they, since theyWere not the one dead, turned to their affairs."