washer

Etymology 1

From Middle English wasshere, wassher, equivalent to wash + -er. Cognate with Dutch wasser, German Wäscher.

noun

1. Something that washes; especially an appliance such as a washing machine or dishwasher.
   A £1.2 million carriage washer has opened at Norwich Crown Point, enabling Greater Anglia to clean its 58 Stadler trains. It is one of two new washers (the other is for '720s' at Southend), […] January 13 2021, “GA opens new carriage washers”, in RAIL, issue 922, page 15
2. A person who washes (especially clothes) for a living; a washerman or washerwoman.
3. A person who washes his or her hands compulsively, as a symptom of obsessive-compulsive disorder.
4. A face cloth.

Etymology 2

Unclear. First recorded in the 14th century.

noun

1. A flat disk, placed beneath a nut or at some joint, to distribute pressure, alleviate friction or prevent leakage.

verb

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