BM 

"bowel movement" but in this case used as an adjective when being annoyed for fed up with a certain person.

Ellen has been such a BM lately, shes on my nerves.

BM by Seamus O'Connell April 30, 2008

BM 

Music: The abbreviations "BM" are known amongst metal enthusiasts as Black Metal. The same follows for it's widely unknown subgenres USBM (United States Black Metal) and NSBM (National Socialist Black Metal). Although, NSBM itself is hotly debated whether or not it belongs to the older BM idealologys. Any other abbrevations outside Black Metal's offspring are considered to be jokes.

If you think Cradle of Filth or Children of Bodom are BM.. do yourself a favor and kill yourself.

BM by _aeon July 7, 2006

bm 

a bitch move or bowel movement. context will decide the official definition.

Kayla: Wow that was a huge BM by Claire.
Chris: Do you mean bowel movement or bitch move? Your sentence was pretty hard to decipher.
Kayla: Bowel movement. Claire just took a huge dump.
Chris: But I though girls didn't poop?

bm by thecabbageninja September 26, 2011

BM 

Big Man

Used in south Dublin area to show gratification to their peers.
“Gary did you see Johnny last night what a BM”
“I know Jordan such a BM”

BM by The BM March 31, 2019

BM 

BASTARD MENOPAUSE - when partner leaves someone due to them going through menopause

going through a BM rn

BM by imabittystoned January 9, 2023

BM 

Baby momma

say that broad your BM

BM by SanScuro April 10, 2016

BM 

Abbreviation for trve kvlt Black Metal

Have you listened to the latest Naglfar album, it was trve kvlt BM

BM by Omnimaniac April 19, 2015