(1):
(n.) A general name applied to various insects belonging to the Hemiptera; as, the squash bug; the chinch bug, etc.
(2):
(n.) One of various species of Coleoptera; as, the ladybug; potato bug, etc.; loosely, any beetle.
(3):
(n.) An insect of the genus Cimex, especially the bedbug (C. lectularius). See Bedbug.
(4):
(n.) A bugbear; anything which terrifies.
(5):
(n.) One of certain kinds of Crustacea; as, the sow bug; pill bug; bait bug; salve bug, etc.