miller's-thumb

[ mil-erz-thuhm ]
/ ˈmɪl ərzˈθʌm /

noun

any of several small, freshwater sculpins of the genus Cottus, of Europe and North America.

Origin of miller's-thumb

1400–50; late Middle English milneres thume; the fish is so called from its thumblike head

British Dictionary definitions for miller's thumb

miller's thumb

noun

any of several small freshwater European fishes of the genus Cottus, esp C. gobio, having a flattened body: family Cottidae (bullheads, etc)

Word Origin for miller's thumb

C15: from the alleged likeness of the fish's head to a thumb