Very tight, compressing pants that deplete your seamen count.
"Dude, that guy had some major sperm killers on at H&M"
by iceteaIceedout September 07, 2014
pants that are worn by males that are too hot are too tight; usually refered in the first person
"man I should not have worn these sperm killers to the golf course today."
by peeroni May 11, 2008