bug

n. a concealed microphone or listening device or other audiosurveillance device.

install such means for audiosurveillance: the embassy had been bugged for several months.

See the Introduction, Abbreviations and Pronunciation for further details.

A widely used word in medieval and Elizabethan English for a bogey or anything which scares people; the simple ‘bug’ is now obsolete, though its compound ‘bugbear’ is still well known.