My definition has always been, in Chicago political parlance, it's often used to indicate the boss, the top guy, the go-to-guy for clout, favors, jobs, etc., but when policemen, firemen, tradesmen, news paper reporters and political hacks etc., use the reference they usually mean it in a derogatory way, as in, ("Oh yeah, he's a "Big McGaffer"?) In this usage, they mean he's an obnoxious, big mouth who thinks he's a big shot, often looked upon as blow-hard, fool, or a phony politician wannabe? A mope, as in "Mickey the Mope", another Chicago classic, pretty much inter-changeable with "Big McGaffer"! A guy who thinks he's all that! ("Dat friend a yours thinks he's a "Big McGaffer", he ain't nut'in but a ,,,,mope"!)

The word is probably spelled as "McGaffer", but it's usually pronounced "MA"-Gaffer! In Chicago anyways!
"Dat friend a yours thinks he's a "Big McGaffer", he ain't nut'in but a ,,,,mope"!

Your brother-in-law thinks just cause he works for the city, he's a Big McGaffer"!
by The Big McGaffer! September 17, 2013
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In 18th Century Irish lore, the object of Lord Benedict's unsavory male affections.

Also, more recently, can be simply referred to as a Benedict.
Look at those fine McGaffers over there!
by TMS Eng May 24, 2011
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