What is the meaning of Knacker?

One who makes knickknacks, toys, etc.

One of two or more pieces of bone or wood held loosely between the fingers, and struck together by moving the hand.

A harnessmaker or saddlemaker; their place of business (e.g., saddlery).

One who slaughters and (especially) renders worn-out livestock (especially horses) and sells their flesh, bones and hides.

One who dismantles old ships, houses, etc. and sells their components.

A member of the Travelling Community; a Rom (Gypsy).

A person of lower social class; a chav, skanger, or similar.

A testicle.

An old, worn-out horse.

A collier's horse.

To tire out, exhaust; to beat up and use up (something), leaving it worn out and damaged.

To reprimand.

Source: wiktionary.org