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
2
a wire stretched close to the ground that activates something (a trap or camera or weapon) when tripped over
双语例句
1
The dogs scampered around him, their tails like trip-wires at his feet.
狗在他身旁边蹦蹦跳跳；尾巴就像脚上绊脚线。
2
Empathy not only clues you in to what your subject wants to hear, it will help you avoid stepping onto tripwires that will trigger their suspicions.