Originated in Newfoundland. Similar use as cunt but not as nasty. For people who don't like to call people the big 'c'. Probably a combination of cunt and onion (something to do with smell maybe?)
Man that guy is such a friggin' cunion.
by Vachon Man October 11, 2005
A hideously smelly vag.
I nearly puked when I got a whiff of Shirley's cunion fumes.
by Cunion Fumes August 24, 2011