Co-boyfriend

When a girl's boyfriend is emotionally distant/abusive, and she doesn't want to just end the relationship, she may seek the comfort of a co-boyfriend. The co-boyfriend hears her complaints, and this allows the broken relationship to continue on a bit longer.

Trina's boyfriend doesn't listen to her problems, so she talks to her co-boyfriend Jack about how shitty her boyfriend is instead of just DTMFA (dumping the motherfucker already).

co-grandniece-in-law

Spouse's grandnibling's wife.

My co-grandniece-in-law is a good person.

co-grandniece-in-law

Spouse's grandnibling's wife.

co-grandniece-in-law.

cos

harry potter and the chamber of secrets shortened

“i just watched cos”
“ew that’s the worst harry potter film”

Cos

Companies

Survey shows 38% of cos intend to hire job seekers.

Cos

Short abbreviation of "Broncos" or "Denver Broncos". Used primarily on Twitter and Instagram.

Player: Broncos Country I'm here!!

Fan: Hell yeah so excited you're on the Cos!!

cos

a runescape clan, that likes to explore each others dungeons, also means "Council Of Saradomin"

person 1: dude, we went to war with you guys last night, you guys raped us! Cos: why, yes we did