Final answer:
The buzz saw in the poem symbolizes life's sudden and unexpected cruelty, underscoring the unpredictability and fragility of human existence.
Step-by-step explanation:
The buzz saw in "Out, Out—" by Robert Frost symbolizes the sudden cruelty life can inflict. It acts as a grim reminder of life's unpredictability and the fragility of human existence. The poem conveys a narrative about a young boy whose life is tragically cut short by an accident with the saw. This tragic event highlights how quickly an ordinary day can turn into one of sorrow and loss due to sudden, unforeseen events.