/ Dictionary / Index B billycock: Meaning and Definition of Find definitions for: bil•ly•cock Pronunciation: (bil'ē-kok"), [key] — n. Chiefly Brit. Informal. a derby or a hat resembling it. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. billy club billy goat Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language