Final answer:
Personification is a figure of speech in which non-human objects or abstract ideas are given human characteristics. The figure of speech used in the sentence 'the stood up to the onslaught' is personification.
Step-by-step explanation:
The figure of speech used in the sentence 'the stood up to the onslaught' is personification. Personification is a figure of speech in which non-human objects or abstract ideas are given human characteristics. In this case, the word 'onslaught' is being personified as something that the subject 'stood up to', which means that it is being treated as a human opponent.