Slayin' Yams is a synonym to words and phrases commonly used for sex. Such as: Fucking, Getting ass, Cheeks, Buns, so on... Only the broest of the bro's can use this term.
Guy1:Yo, what did you do this weekend?
Guy2: Went to the shore with some chicks.
Guy1: Nice! You get some?
Guy2:Yea dude, I was slayin' so many yams Guy1: Sweet, you stay slayin' yams man.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.