varnish (n.)

mid-14c., from Old French vernis "varnish" (12c.), from Medieval Latin vernix "odorous resin," of uncertain origin, perhaps from Late Greek verenike, from Greek Berenike, name of an ancient city in Libya (modern Bengasi) credited with the first use of varnishes. The town is named for Berenike II, queen of Egypt (see Berenice). Figurative sense of "specious gloss, pretense," is recorded from 1560s.

late 14c.; see varnish (n.). Related: Varnished; varnishing. Century Dictionary defines varnishing day as "A day before the opening of a picture exhibition on which exhibitors have the privilege of retouching or varnishing their pictures after they have been placed on the walls." The custom is said to date to the early years of 19c.