Synonyms of watertight

1 Syllable

nice, sure, strict, sound, true, real, just

2 Syllables

correct, factual, solemn, proofer, amen, valid, utter, exact, perfect, faithful, proper, righteous

3 Syllables

impervious, out-and-out, rigorous, undoubted, inerrant, complete, thoroughgoing, authentic, punctilious, veracious, hermetic, unerring, padlocked, genuine

4 Syllables

imperviable, unpierceable, absolute, admissible, infallible, veritable, impermeable, veridical, undistorted, unmistaken

5 Syllables

satisfactory, indubitable, immaculate