= watertight, adj. 1.

Impervious to water, not leaking; watertight. Also occasionally airtight.

Constructed, fastened, or fitted so as to prevent the passage or leaking of water.

So close in texture or structure as to keep water out; esp. of a ship or boat, so closely compacted and well caulked as to be watertight. Now dialect.

Made or constructed so that water cannot enter or escape; impermeable to water; watertight. Also figurative and in figurative contexts.

Of a thing: impervious to water, impermeable. Also occasionally of a person: provided with, or wearing, waterproof clothing.

watertight.

Impervious to moisture or damp.

(In sense 3.)

rendered impervious to damp.