lave

The verb is derived from Middle English laven (“to bathe, wash; to bail or draw water, drain, exhaust; to dampen, wet; to pour; of water, etc.: to flow, stream”), and then partly:

from Old French laver (“to be washed; to wash”) (modern French laver (“to wash (oneself)”)), from Latin lavāre, the present active infinitive of lavō (“to bathe, wash; to dampen, wet”), ultimately from Proto-Indo-European *lewh₃- (“to wash”); and

from Old English lafian (“to bathe; to make wet; to ladle out; to pour”), from Proto-West Germanic *labōn (“to refresh, revitalize; to strengthen”); further etymology uncertain, possibly from Latin lavō (see above) but this does not explain the change in meaning from “to wash; to wet” to “to refresh; to strengthen”. Perhaps Old English lafian is derived directly from the Latin word, and Proto-West Germanic *labōn and words in languages derived from it such as Dutch and German are coincidentally similar to the Old English word.

The noun is derived from the verb.