trip wire

1. 1.

   a small military force that serves as a first line of defense; if they become engaged in hostilities it will trigger the intervention of stronger military forces

   Broadermilitary unit

   military

2. 2.

   a wire stretched close to the ground that activates something (a trap or camera or weapon) when tripped over

   Broaderwire

Questions about trip wire

What does trip wire mean?

trip wire means "a small military force that serves as a first line of defense; if they become engaged in hostilities it will trigger the intervention of stronger military forces". That is the primary sense; the word has 2 in total, listed in full on this page.

Is trip wire a common word?

trip wire is banded "Uncommon" — turns up in careful writing rather than conversation. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.