WordNet records no synonym and no antonym for trip wire. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
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
a wire stretched close to the ground that activates something (a trap or camera or weapon) when tripped over
Synonyms, antonyms and the broader and narrower relations for trip wire come from Princeton University’s WordNet. Full sources and licences.