tart [ME] Today a tart is likely to be filled with jam or fruit, but in medieval times it was a savoury pie. In mid 19th-century slang it was an affectionate word for a woman (probably as an abbreviation of sweetheart), but by the end of the century it was being applied disparagingly to a prostitute or promiscuous woman. Tart up, ‘to dress up ostentatiously’, came from this use in the 1930s. Tart [OE] meaning ‘sharp to the taste’ is a different word. It originally meant ‘harsh, severe’, especially in reference to punishment, but is of unknown origin.