The Oxford Thesaurus An A-Z Dictionary of Synonyms - bug n.

1) insect, beetle, larva, grub, caterpillar, butterfly, mosquito, fly, spider, Colloq Brit creepy-crawly, US no-see-em: There's a bug on your collar. 2) microbe, germ, virus; disease, affliction, illness, sickness, ailment, disorder, malady, infection; condition, complaint, infirmity, indisposition: She's caught some kind of bug and won't be in for a few days. 3) obsession, craze, fad, mania, rage: Almost everyone in those days succumbed to the hula hoop bug. 4) enthusiast, faddist, fan, fanatic; hobbyist: She's turned into a fruit machine bug. 5 listening device; microphone, transmitter, electronic eavesdropper, tap: They planted a bug in the ambassador's telephone. 6) fault, error, mistake, failing, shortcoming, Colloq hang-up, glitch: There's a bug in the program that's preventing the list from being sorted. They can't market the device till they've ironed out all the bugs. --v. 7) annoy, irritate, pester, irk, harass, bother: I wish Mum'd stop bugging me about my homework. 8) tap, spy on: They bugged her phone and recorded all her conversations.