screw [LME] There is debate as to whether screw comes from Latin scrofa ‘a sow’, later ‘female screw, nut’, or from Latin scroba ‘a dug hole’. Possibly the two words influenced each other. Scrofa is also the source of scrofula [LME], a disease people thought breeding sows were particularly susceptible to. Scrofula was also called the King’s Evil, because kings were traditionally thought to be able to cure it. The slang sense ‘to have sex’, dating from the early 18th century, is probably the source of screw up meaning ‘to mess up’ [M20th]. It was a US euphemism for f— up.