The art of projecting a 'cone' using solely the power of one's semen when ejaculating. A 'cone' can typically be formed using a rolled up piece of paper into the shape of a cone, but more advanced users have been known to have used cloth, cardboard and even, in some more extreme cases, scrap metal.
Boy: Oh yeah, this is going to make a great snowcone!
*Rolls circular piece of paper into cone-like shape and places it upon his penis, begins masterbating and ejaculates, sending the cone flying into the air*
Girl: Ow! You just snowconed me in the eye!