An antiquated, schoolyard term denoting the grasping/throttling of male genitals in a rapid, yet even, measure; so to resemble the beating heart of a rabbit. Believed to have originated in the late 1980's or early 1990's, and may in fact be regional to the greater northeast, though this is admittedly speculative.
(verb) (noun) (adj) - To bring a organ of a sheep from the biology wing to the lunch room and leave it for others to mess with and get in trouble with.
1. Matt brought the Sheep's Heart to the lunch rooom and some of us got In-School-Restriction for being part of it.
2. That Sheep Heart really fucked us, now we're in trouble.