Watertightness

Part of speech: noun

Definitions

1. The attribute of a material that prevents water from penetrating The state of a system designed to resist water infiltration The quality of an object that ensures no water can enter or damage it
2. The characteristic of an item that stops water from getting inside
3. A property of objects or materials that keeps water from passing through

Etymology: Watertightness is a plain compound: "water" plus "tight," with the suffix "-ness" added to turn the adjective "watertight" into a noun. "Watertight" is itself a compound describing a joint or container so closely fitted that water cannot pass through, and the sense is literal, built from the tightness of seams in wooden hulls and casks. The suffix has a long pedigree. "-ness" descends from Old English "-nes," which formed abstract nouns from adjectives, so "tightness" and "watertightness" both express a state or quality. The source traces the suffix back to Proto-Germanic forms and ultimately to Proto-Indo-European, but in practice English simply attached this productive ending to "watertight" whenever a speaker needed a name for the quality rather than the thing. Because the word is a transparent formation, its meaning follows directly from its parts: a state of being watertight, the property that keeps water out.