washer

Short definition from Wiktionary

Noun

1. 1
   Something that washes; especially an appliance such as a washing machine or dishwasher.
2. 2
   A person who washes (especially clothes) for a living; a washerman or washerwoman.
3. 3
   A person who washes their hands compulsively, as a symptom of obsessive-compulsive disorder.
4. 4
   A face cloth.
5. 5
   A flat piece of material, often of metal and often an annulus, placed beneath a nut or at some joint, to distribute pressure, alleviate friction, provide directionally differentiated friction (e.g. making the nut turn counter-clockwise only with difficulty), or prevent leakage.

Verb

1. 1
   To fit (a mechanical device) with a washer.

Proper noun

1. 1
   A surname.