Bull Semen Share definition Flag 1) More severe than bull shit. 2) A way of expressing how wrong something is when no other word seems to fit. See also shananagins Ron: Yeah, I just started dating karen. John: AH! Bull semen! We fucking broke up 2 days ago! Bull Semen by S3H November 2, 2008 0 0 Get merch Get the Bull Semen mug. Buy Now — $32.95 See more merch