knacker

Short definition from Wiktionary

Noun

1. 1
   One who makes knickknacks, toys, etc.
2. 2
   One of two or more pieces of bone or wood held loosely between the fingers, and struck together by moving the hand.
3. 3
   A harnessmaker or saddlemaker; their place of business (e.g., saddlery).
4. 4
   One who slaughters and (especially) renders worn-out livestock (especially horses) and sells their flesh, bones and hides.
5. 5
   One who dismantles old ships, houses, etc. and sells their components.
6. 6
   An itinerant person, especially one of Irish Traveller heritage.
7. 7
   A person of lower social class; a chav, skanger, or similar.
8. 8
   A testicle.
9. 9
   An old, worn-out horse.
10. 10
    A collier's horse.

Verb

1. 1
   To tire out, exhaust; to beat up and use up (something), leaving it worn out and damaged.
2. 2
   To reprimand.