Short for self injurious behavior. Similar to sh (self-harm) except sib is doing something that hurts themselves, but isn't meant to inflict harm. But sh is trying to inflict harm on themselves.
Me: when I was younger I used to sib
Person: what's that?
Me: something I did to hurt myself but I didn't mean to
Person: isn't that sh?
Me: no I didn't do that until later in life, my sib was hitting my head when I didn't get my way
Person: what's that?
Me: something I did to hurt myself but I didn't mean to
Person: isn't that sh?
Me: no I didn't do that until later in life, my sib was hitting my head when I didn't get my way
by That_Trans_Guy_Denki May 18, 2022
Get the Sibmug. Sib is another word for sibling
by Purr vanilla cookie October 20, 2021
Get the Sibmug. 
Gender-inclusive term of endearment used among anyone who loves someone else in whatever capacity (platonic, familial, romantic, etc.). An alternative to "bro" or "sis".
Person A: Hey... *thinks* wait I don't know their pronouns *thinks* sib, what's up?
Person B: The sky lmaooo :P
Person B: The sky lmaooo :P
by I Am Princess X June 20, 2020
Get the Sibmug. You could call your friend sis or bro, but what about sib? It’s rEvOlUtIoNaRy!
bro= brother
sis= sister
sib= sibling
It’s great for ur non-binary pals
bro= brother
sis= sister
sib= sibling
It’s great for ur non-binary pals
by iamitSIB December 24, 2019
Get the sibmug. by dick fingers January 15, 2023
Get the SIBmug. Short for sibling. Instead of saying bro or sis to a close person/relative, you can use this gender neutral word.
by TheRealSlimFati August 18, 2023
Get the Sibmug.