Seems to have been taken from Caribbean English, in which it is (was) used to refer to a gullible person. The word has since undergone several changes in meaning, so that it now depends on which sense of the word the speaker has been exposed to. It was popularized in Scorsese's "Mean Streets" (1972), but when Johnny calls Jimmy a mook, it causes confusion: "Nobody knows what a mook is" even appears in the script.
mook (n.)
"This type of student, rigorously following a daily assignment schedule and graphing his grades on the wall, is a never common but somewhat frequent phenomenon. The ‘grind’, ‘mook’, or ‘weenie’ superficially seems to satisfy the demands of Yale, but in many ways he is not alive to the spirit of the place."
--Yale Alumni Magazine, Jan. 21, 1958

"Call them knuckleheads or young white guys; Spin magazine lambasted them with the term ‘mooks’, a label that has since been picked up as a badge of honor."
--NY Times Magazine, Aug. 6, 2000: 39/2
by D.R.M. December 5, 2006
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1. A loosely adhered-to marketing term used to refer to an adolescent to twentysomething male who shows off and makes a scene of himself. A mook personifies the adoption of trends for the sake of commercialism and the mindless celebration of childish masculinity. Particularly featured on mtv

2. That guy at your high school who used to be really popular when he was an underclassman, but now he sleeps with popular girls to get attention.
by brap August 27, 2004
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(noun) - a less powerful enemy, easily dealt with, often appearing in large groups to present some challenge; a thug. Used especially in the context of pen-and-paper roleplaying games.

Background:
- Possibly first used in the roleplaying milieu in the game "Feng Shui" by Robin Laws.
- Possibly derived from "mook jung", the wooden training dummy used in wing chun style martial arts.

Note:
Other definitions for this word likely exist. Search also under "mook (n.)".
Player 1: Hey did you're all's characters get to face off last week against the lich-mage-king-of-death?
Player 2: Naaa. We just had them beat up on a bunch of zombie mooks.
Player 1: Guess I didn't miss much then
by Peter K. March 15, 2005
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A retarded woman. most likely incompetant or just fuckin stupid
"I cant believbe they make me work with this fuckin mook
by Gimpy Pete March 15, 2005
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A fat, clown nosed, stinky, slutty, inconsiderate witch and cheap prostitute.
I've only got a few cents left...all I can afford is mook, and no one wants that.
by spiderman July 13, 2004
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