Skip to main content
Abbreviation for "Chamber of Secrets", the second book on J.K. Rowling's Harry Potter.
"cos is my fav book"
COS by Raqueli88 September 5, 2006
Related Words
An abbreviation for Chief of Staff, the best drinker in a group of political workers.
John: Eric was really hammered last night after the fundraiser. He must have had 20 beers.

Jason: Yeah, he’s the COS.
COS by Bamalama Johnson April 7, 2008
aim conversaton:
Jimz3213: yeah. i totally banged her sister last night.
Susiexxoox4: yeah well. cos...

how is your moms rehab going?
Cos by SUSIEEEEEEEEE November 10, 2007
Abreviation for the Church of Satan, an official organization referring to those that worship the devil.
He is a member of the CoS.
Just like FBC is First Baptist Church...
CoS by Heidi April 26, 2005
a term in Hebrew for "cup"
Miriam has a big cos.
cos by Johnny February 21, 2004