Word Origin & History
1404, from M.Fr. escroue "nut, cylindrical socket, screwhole," of uncertain etymology; not found in other Romanic languages. Perhaps via Gallo-Romance *scroba or W.Gmc. *scruva from V.L. scrobis "screw-head groove," in classical L. "ditch, trench," also "vagina" (Diez, though OED finds this "phonologically
impossible"). Kluge and others trace it to L. scrofa "breeding sow," perhaps based on the shape of a pig's penis (cf. Port. porca, Sp. perca "a female screw," from L. porca "sow"). A group of apparently cognate Gmc. words (M.L.G., M.Du. schruve, Du. schroef, Ger. Schraube, Swed. skrufva "screw") often are said to be Fr. loan-words. Sense of "means of pressure or coercion" is from 1648, probably in ref. to instruments of torture (e.g. thumbscrews). Meaning "prison guard, warden" is 1812 in underworld slang, originally in reference to the key they carried. To have a screw loose "have a dangerous (usually mental) weakness" is recorded from 1810. Screwy (1820) originally meant "tipsy, slightly drunk;" sense of "crazy, ridiculous" first recorded 1887.
"to twist (something) like a screw," 1599, from screw
(n.). Slang meaning "to copulate" dates from at least 1725, on the notion of driving a screw into something. Meaning "a prostitute" also is attested from 1725. Slang meaning "an act of copulation" (n.) is recorded from
1929. First recorded 1949 in exclamations as a euphemism.