Semen that has been inside of a vagina and rubbed on a nape, where it receives sweat in the mix, and often has the consistency of warm butter, hence "buttered".
Good lord! That buttered nape seed was rubbed all over my good pants! It's like a crotch sauce with butter!
The penis seed is a mythical item in which a female can place in her vagina to grow a penis. As of now it does not really exist, but maybe with all these new technological advancements in the world of science, the penis seed could become a real item on your list of things to get at wal mart!
Mary used to just be a dyke, then she used a penis seed, and now she's a transexual.