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miller's-thumb

American  
[mil-erz-thuhm] / ˈmɪl ərzˈθʌm /

noun

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

miller's thumb British  

noun

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of miller's-thumb

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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.