A semi-formal dance for which girls get far too dressed up (gowns and fancy jewelry, etc.) and for which many guys come severely under-dressed. Humiliating, yes. Enjoyable, perhaps if you come drunk.
"Dude, did you see that girl's dress at cotillion? she swears she's at a prom?"

"Yeah man, all I wore was some khaki's and my dad's dress shirt."
by Deebsies March 02, 2009
Get a Cotillion mug for your dog Beatrix.
A dance only dumb people go to.
Abbey: Ooh let's go to my Cotillion!
Abbey: What's that?
by TheGirlWhoHates May 03, 2010
Get a Cotillion mug for your Facebook friend James.
A traditional filipino celebration similar to a quinceañera, but for a girl's 18th and a boy's 21st birthdays. Girls are usually the ones who make a big deal out of it. It's not a required thing, but girls with rich or semi-rich families will usually over-do these celebrations and make their cotillion look like a wedding and have videos and pictures of the celebration on social websites, only to get ridiculed by the cost and the amount of seriousness those said girls put into their cotillion.
Girl 1: "Check out my cotillion!"
Girl 2: "Omg this is for your 18th birthday? I didn't even get a cake for my birthday."
Girl 1: "FOR YOUR INFORMATION It's a filipino tradition."
Girl 2: "Okay spoiled girl..."
by icuthrumywindow December 21, 2011
Get a cotillion mug for your cousin Jerry.
Punishment for failing to answer a feat of strength when challenged by another man (generally at a bachelor party or other like event).

The coward is required to take three bull-rider shots in a row (the cotillion).
Peter challenged Ross to an arm wrestling contest and Ross was scared he would lose so he rejected the challenge.

Ross is thus a coward and is required to complete the coward's cotillion as restitution for his cowardice.
by BigVR June 03, 2009
Get a Coward's Cotillion mug for your barber Manafort.
Jeremy and I put on our frilliest outfits to attend the Rainbow Ball. It was a cotillion of cocksuckers!
by SJ@24 July 10, 2009
Get a cotillion of cocksuckers mug for your guy Jerry.