technical any of an order of insects with mouthparts that enable themit to pierce and suck: order Hemiptera
any creeping or crawling insect commonly considered unpleasant or a pest, e.g. a bedbug
informal any micro-organism, esp a disease-producing bacterium, or a disease caused by it
an unexpected defect or imperfection
a fault in a computer program
informal a temporary enthusiasm; a craze
a concealed listening device
[Middle English bugge spectre, goblin, of Scandinavian origin]