- so snugly put together that no water can get in or through
- that cannot be misconstrued, refuted, defeated, nullified, etc.; flawless: a watertight excuse, plan, etc.
See watertight in American Heritage Dictionary 4
- So tightly made that water cannot enter or escape.
- Having no flaws or loopholes; impossible to fault, refute, or evade: a watertight alibi; a watertight contract.
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