say it: WAW-tur-tahyt
watertight is an adjective meaning "not allowing water to pass in or out". It carries 2 recorded senses.
not allowing water to pass in or out
without flaws or loopholes
“an ironclad contract”
“a watertight alibi”
“a bulletproof argument”
Definitions, synonyms and semantic relations for watertight come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.