look up any word, like blumpkin:
 
2.
A warning given near the end of coitus, usually directed toward a female from a male
Guy having sex with girl: "I'm gonna cum!"
Girl: *Covers face or whatever else she doesn't want the splooge to get on*
by Mitch Tyler September 03, 2009
 
1.
A common phrase used during the act of sex or masturbation, usually exclusively used by men. It signifies appraoching orgasm and/or ejaculation. The ending "cum" is a play on the word come, and in turn derived from the common term cum.
"Oh god! I'm gonna cum!"
by thedoctor44 May 31, 2007