Used to represent the value of nothing, zero (0), zip.

To press the button on one's ambulance pager to signal a response to the nightly tone tests.

Zilch is another word for zero or minuscule.

A word used to describe nothingness or an absence of something.

The zilch is a part of the cock.

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

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.

nothing, having a value of nothing, zero