/ Dictionary / Index L loco: Meaning and Definition of Find definitions for: lo•co Pronunciation: (lō'kō), [key] — n., pl. v., adj. -cos, -coed, -co•ing, —n. locoweed. an insane person; maniac. locoism. —v.t. to poison with locoweed. to cause to be insane or crazy. —adj. out of one's mind; insane; crazy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: loco (Thesaurus) Lockyer loco citato* Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language