OC 

OC means both original character and out of character. This is mostly used in fan fictions to explain to the readers that an original character from the publish work (ex; Harry Potter) is not going to be acting like they usually do.

Severus Snape is not being snarky ,and he is being nice so he is OC.

OC by Kurama_Bookworm127 July 18, 2013

OC 

In the My Little Pony Fandom (Or any other fandom, mlp being most common) An OC stands for Own Creation/Original Character. The term refers to someone when they creator their own character in a fandom, some can be found on DevaintART or tumblr. The OCs are often given names, or adopted.

Casey: "Angie, I love your Hunger Games OC."
Angie: "Thanks! I hand drew it too."

OC by HaloBrony April 15, 2015

OC 

Short for Open Crib. Where there is a lack of parental supervision, and lots of alcohol / drugs are usually being consumed while the parents aren't home. OC's usually get aggressive real quickly.

Popular amongst 15-25 year olds

Yo man, who has the OC right now? I just got out of work and would love to kick back with some blunts and brews right now.

OC by anonymous 1157 July 24, 2016

oc 

oc means 'original crew'.

man everyone's gathering at the dees tommorow, it's gonna be the oc chilling like old times.

oc by senru July 3, 2004

OC 

premature ejaculation, that is, to cum "Out (of) Cunt"

I was in such a hurry with her that I OC'd.

OC by Jake March 24, 2004

OC 

O'Charleys (the restaurent)

last night we ate at OC

OC by mkayyy August 23, 2006

OC 

movie co-starring jack black

Jack Black's character "'she was like i hate my job, i'm gonna burn this mother down' and i was like 'you better not!'"

OC by shern July 27, 2004