What type of literary term is But the regiment was a machine run down?

The phrase "But the regiment was a machine run down" uses a metaphor to describe the regiment.

Here's why:

* Metaphor: A metaphor is a figure of speech that compares two unlike things directly, without using words like "like" or "as."

* Comparison: The phrase compares the regiment to a "machine run down."

* Meaning: This suggests that the regiment is exhausted, worn out, and perhaps malfunctioning due to the stress of war or other challenges.

The use of metaphor makes the writing more vivid and impactful, creating a strong image of the regiment's state.