Trenches def
A trench is a long, narrow excavation in the ground. Trenches may be dug for utilities, drainage, or military protection. In everyday figurative language, being in the trenches usually means dealing directly with difficult work or practical problems.
Meaning and context
The literal and figurative meanings share an image of being down in the work rather than observing it from a distance. A construction report about a trench probably concerns an actual excavation. A colleague describing a demanding week as life in the trenches is more likely using a metaphor.
Examples and usage
The crew dug a trench for the cable is literal. Our support team has been in the trenches all week describes demanding frontline work. These examples show how the surrounding nouns and actions distinguish the meanings.

What to check
Do not treat every figurative use as a reference to a specific war. The phrase can evoke military experience without making a precise historical claim. For an excavation, depth, protection, and access are safety matters that a dictionary definition cannot resolve.
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