The most pathetic response anyone can give you during a text or instant message conversation.

Mostly used by immature girls that don't actually give a fuck about what you're doing...especially if they couldn't even type out something longer then a 3 letter response.

2nd in pathetic to "lol", people that use "nmu" in a serious form deserve to be forever deprived from their cell phones and computers.

If a response as pathetic as "nmu" is used as a response, you should not even respond in the first place.
Guy: Hey what's up??
Girl: nmu
Guy: Wow that's a fucking pathetic response
Girl: Soorrryyy I'm (insert bullshit excuse here)
by ItstheWaveTV September 23, 2009
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Online lingo; abbreviation for "Not much, you?"
-"What's up?"
-"nmu"
by markotsay7 May 24, 2003
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Originating from the phrase "nm u" in response to asking a question similar to "What's up?", an NMU is a person who seriously does not give a flying fuck about what you have to say. These people often seem uninterested over text, and would rather be doing whatever they are doing. They are the apotheosis of not giving a shit. NMU's often use terms such as 'same', 'wow!!', and 'cool' etc. Use 'lol' to compensate for the complete 'I don't give a shit' in their soul. Occasionally will use sarcastic exclamation marks. Never uses capitalized letters, unless screaming.
Guy 1: Hey, what's up?
Girl 1: nm u
Guy 1: Uh, just sort of watching TV.
Girl 1: wow thats really cool!!!!!!
Guy 1: Fuck this, you're an NMU.
by Alahu Snackbar December 1, 2014
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The emu's more popular and successful cousin; commonly used in AIM slang.
Person: hey what's up?
Other Person: nmu?

OR, EVEN BETTER...

Person: hey what's up?
Other Person: NMU ATTACK!
by Teh Kt-zors! May 30, 2007
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