Brit. <英>
1
- a person whose business is the disposal of dead or unwanted animals, especially those whose flesh is not fit for human consumption处理（尤指其肉不宜食用的）老弱家畜（或其尸体）的人。
2
- ( knackers) vulgar slang testicles〈粗俚〉睾丸。
3
- Irish informal an uncouth or loutish person〈爱尔兰, 非正式〉粗暴无礼的人; 恶狠狠的人。
with obj.［often as adj. knackered］
1- Brit. informal tire (someone) out; exhaust〈英, 非正式〉使（人）筋疲力尽：
you look absolutely knackered.
你看上去完全筋疲力尽了。
1.1
- damage severely严重损害。
词源
late 16th cent. （originally denoting a harness-maker, then a slaughterer of horses）： possibly from obsolete knack 'trinket'. The word also had the sense 'old worn-out horse' （late 18th cent.）. Sense 2 may be from dialect knacker 'castanet', from obsolete knack 'make a sharp abrupt noise', of imitative origin. It is unclear whether the verb represents a figurative use of 'slaughter', from sense 1, or of 'castrate', from sense 2.