"to hurl or fling down," 1520s, a back formation from precipitation or else from Latin praecipitatus, past participle of praecipitare "to throw or dive headlong," from praeceps "steep, headlong, headfirst" (see precipice). Meaning "to cause to happen, hurry the beginning of" is recorded from 1620s. Chemical sense is from 1620s; meteorological sense first attested 1863. Related: Precipitated; precipitating.

c.1600, from Latin praecipitatus, past participle of praecipitare "to throw or dive headlong" (see precipitate, v.). Meaning "hasty" is attested from 1650s. Related: Precipitately.

1560s, probably a back formation from precipitation.