(NM) 

(NM) is normally used in bios on social media sites like Twitter and Tumblr. NM stands for "Not Mine" and refers to the user's profile picture and/or profile header not belonging to them. HNM (Header) and PFNM (Profile Picture) is used for when the header or profile picture specifically.

(NM) Hello! I am a person! Welcome to my Account!

Hello! I am person! Welcome to my Account!
NM - Minor - Female

(NM) by Dabbibro March 3, 2021

/nm 

Not mad or not mean. Used after messages or posts over text to indicate tone.

A: please don't send me friend requests if i don't know you irl /srs /nm

/nm by voloutia June 2, 2021

nm 

perfect way of killing a conversation.

hey
hi
whatsup?
nm.

nm by meg4tr0n May 19, 2008

nm 

Not Much. Mostly used on im (instant messaging) e.g msn, aim, skype.

fred: Heyy up to much?
Tim: nm you?
fred: nm just chatting to you
Tim: oh cool

nm by MsnAddict_x May 1, 2009

/nm 

/nm stands for /notmad. It is a tone indicator that is mainly used on twitter to show if they’re not mad, just curious. An example of using this is asking why a person did something.

“Hey, why did you do that? /nm Just curious.”

/nm by WintiBear November 16, 2021

nm 

An abbreviation of "not much" or "nothing much". It is most commonly used in instant messaging conversations as an easy and thoughtless answer to the question what's up.

Some people also use it as an abbreviation for "nevermind", but "nvm" is more popular.

Typical start of an MSN conversation:
Jack: hey
Jill: hey
Jack: sup?
Jill: nm u?
Jack: nm
Jill: cool
Jack: yup
Jack: (starts talking about something)

nm by Laurenn January 2, 2009

nm 

an annoying/lazy way of saying "Oh, I was just sitting here with my thumb up my ass, waiting for you to ask me what I was doing. In fact, let's just stand here and piss away 3 minutes of our lives talking in unclear ambiguous terms about how our day is, what we did five minutes ago, and what we plan on doing five minutes from now."

Person 1: Whazzzz up??
Person 2: nm

nm by Anonymous November 5, 2002