c.1150, "person of ribald speech," also "person fond of abusive language," from O.N.
skald "poet" (see
skald). The sense evolution may reflect the fact that Gmc. poets (like their Celtic counterparts) were famously feared for their ability to lampoon and mock (e.g.
skaldskapr "poetry," also, in Icelandic law books, "libel in verse"). From the beginning, used especially of women. The verb is attested from 1377.