10 letters · 17 points in Scrabble
adjective not allowing water to pass in or out
adjective without flaws or loopholes
originFrom water + tight. Compare Scots wattirticht (“watertight”), West Frisian wetterticht (“waterproof”), Dutch waterdicht (“waterproof, watertight”), German wasserdicht (“watertight, waterproof”), Danish vandtæt (“watertight”), Swedish vattentät (“watertight, waterproof”).
Etymology from Wiktionary, CC BY-SA 3.0