It is an acronym meaning Wind-Up Merchant.

It refers to someone who posts on message boards and newsgroups with the intention to cause as much disruption as possible by goading others.
He's a WUM, just ignore his posts.
by Nataku November 3, 2005
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= hot
= sexy
= attractive
very duplicitous in its definition
Louange is wum.
by zooplankton zoloretto January 4, 2021
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dude1: bush is a bloody errorist..
dude2: wum?
dude1: an idiot.. he keeps makin mistakes
by raz2416 September 4, 2007
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"Hey look, it's a wum!"

"My favorite candy I gummi wums!"
by Jitterbug May 31, 2014
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The verb form of WUM (Wind-Up Merchant), a predominantly online phenomena of espousing contrary viewpoints purely to string people along and get a reaction from others. A mild-mannered form of trolling.
I know you're just having a laugh, but cut out the wumming, NewFag, or I will ban your ass faster than the angry fist of god.
by B9a May 19, 2011
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"Wum" is the female discharge or female Cum. Womanly cum thus the everyday word WUM.
"Holy crap Bertha, you got wum all over me!"
by ahhhhbigail October 10, 2005
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