Skank

wiktionary

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Origin unknown. Perhaps from skag(“unattractive woman”), but the origins of skag are unknown. [1] Compare scold(“troublesome woman”), skeevy(“disgusting”). Attested from the 1960s. [2]

Originally Jamaican, attested from the twentieth century, but earliest source is uncertain. The verb sense be dishonest is evidently older. Perhaps originally onomatopoeic. The dance senses may come from a resemblance to motorcyclists weaving in and out of traffic. [3] Compare skanker.

Slang word used in Northern England. Origin unknown. Perhaps from etymology 2, above; attested in West Indian and UK black slang from the twentieth century. [4]

etymonline

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skank (n.)

"unattractive woman," 1965, perhaps from skag in this sense (1920s), which is of unknown origin. Verbal meaning "dance to reggae music" is from 1976, probably not the same word but also of unknown origin. Related: Skanking.