Brit.
■ noun
1》 a person who disposes of dead or unwanted animals.
2》 ( ~s ) vulgar slang testicles.
■ verb [often as adjective ~ed ] informal exhaust; wear out.
↘damage (something) severely.
Origin
C16 (orig. denoting a harness-maker): possibly from obs. knack 'trinket'; sense 2 may be from dialect ~ 'castanet'.