miller's thumb(redirected from miller's thumbs)
Any of several small freshwater sculpins of the genus Cottus, having a large spiny head and spiny fins, especially the European species C. gobio.
[From its stocky, thumblike shape (the phrase miller's thumb was originally a folk expression referring to millers who gave short weight by tipping the scales with their thumbs).]
(Animals) any of several small freshwater European fishes of the genus Cottus, esp C. gobio, having a flattened body: family Cottidae (bullheads, etc)
[C15: from the alleged likeness of the fish's head to a thumb]