/stik"euhl bak'/ , n.
any of the small, pugnacious, spiny-backed fishes of the family Gasterosteidae, inhabiting northern fresh waters and sea inlets, the male of which builds and guards the nest. Also called prickleback .
[ 1400-50; late ME stykylbak, equiv. to OE sticol scaly + baec BACK 1 ]