watertight
UK: ˈwɔːtətaɪt | US: ˈwɔːtərtaɪt
adj. Impermeable to water; completely sealed against leakage.
adj. (of an argument or plan) So logically sound that it cannot be disputed or invalidated.
The word "watertight" emerged in the early 17th century, combining "water" (from Old English wæter, derived from Proto-Germanic watōr) and "tight" (from Old Norse þéttr, meaning "dense" or "impermeable"). The fusion reflects a literal sense of being "tight against water," initially used in shipbuilding to describe hulls or compartments that prevent leaks. By the 19th century, it gained figurative use to describe arguments or plans that are flawlessly constructed, leaving no "gaps" for criticism.
The submarine's compartments must be watertight to withstand deep-sea pressure.
The lawyer presented a watertight case, leaving no room for doubt.
Ensure the jar lid is watertight to preserve the food inside.
Their alibi was watertight, so the police dropped the investigation.
The contract's clauses were watertight, preventing any legal loopholes.