var·nish / ˈvärnish/ • n. resin dissolved in a liquid for applying on wood, metal, or other materials to form a hard, clear, shiny surface when dry. ∎  [in sing.] archaic an external or superficially attractive appearance of a specific quality: an outward varnish of civilization.• v. [tr.] apply varnish to: we stripped the floor and varnished it. ∎  disguise or gloss over (a fact): the White House is varnishing over the defeat of the president’s proposal.DERIVATIVES: var·nish·er n.

varnish Solution of a resin or a plastic that dries to form a hard, transparent, protective and often decorative coating. Varnishes may have a matt or glossy finish. Pigments are often added to colour the varnish.

varnish solution of resinous matter used for providing a hard shiny coat XIV; fig. XVI. ME. vernisch — (O)F. vernis :- medL. veronix, -nic- fragrant resin, sandarac, or — medGr. berenī́kē, prob. appellative use of the town-name Berenice (in Cyrenaica).
So varnish vb. XIV. — OF. verniss(i)er, -ic(i)er.