The zilch is exactly the rim of the bell (bell-end), where the shaft of the man's Johnson ends and the bell-end begins.
It is that rim, ridge, edge which is known as the zilch
Jimmy doesn't get head from girls with braces any more in fear of getting his bell-end ripped off by the zilch
When one takes a garbage bag and ties it in a string on knots, then lights them on fire. Miniature fireballs with drip from it as it makes futuristic noises.
Some conflabbed hooligans were holding lit zilches over the balcony at pyromania. One of them hit Max's head. He still has a creepy bubble.