English edit

Etymology edit

From water +‎ fast. Cognate with Scots wattirfast (watertight), West Frisian wetterfêst (waterproof), Dutch watervast (waterproof), German wasserfest (waterproof), Danish vandfast (waterproof), Swedish vattenfast (waterproof).

Adjective edit

waterfast (comparative more waterfast, superlative most waterfast)

  1. watertight
  2. waterproof
    • 1953, August G. Lockwood, Norman E. Stanton, How to Finish Your Attic and Basement Yourself, page 166:
      If you spot paste, and your paper is waterfast, wipe at once with a damp cloth or sponge. If the paper is not waterfast, wipe with a dry cloth.
    • 2000, Nelson Novick M.D, Baby Skin:
      A waterfast sunscreen, in other words, a product that stays on well despite swimming or heavy perspiration, is also advisable.