~ 1
■ verb
1》 measure (the depth of a body of water).
2》 explore or experience fully or to extremes: she had ~ed the depths of depravity.
3》 test (an upright surface) to determine the vertical.
■ noun a lead ball or other heavy object attached to a line for finding the depth of water or determining the vertical on an upright surface.
■ adverb
1》 informal exactly: ~ in the centre.
2》 N. Amer. extremely or completely: they must be ~ crazy.
3》 archaic vertically.
■ adjective
1》 vertical.
2》 Cricket (of the wicket) level; true.
Word History
The word ~ entered Middle English via Old French, from the Latin ~um 'lead'. It shares this root with the words ~er , plummet , and aplomb . A ~er was originally a tradesman who worked with lead, which was formerly used for water pipes. In the Middle Ages plummet denoted a ~ or ~ line; its use as a verb to mean 'fall rapidly' is a 20th-century development. Aplomb entered English from the French phrase à plomb 'according to a plummet': it originally meant 'perpendicularity, steadiness'.
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~ 2
■ verb ( ~ something in ) Brit. install a bath, washing machine, etc. and connect it to water and drainage pipes.
↘install and connect pipes in (a building or room).
Origin
C19: back-form. from ~er .