so‧lid‧i‧ty /səˈlɪdəti, səˈlɪdɪti/ noun [uncountable]
[Word Family: noun: solid, solidarity, solidity, solids, solidification; verb: solidify; adverb: solidly; adjective: solid]

1. the strength or hardness of something:
the solidity of the stone walls

2. the quality of something that is permanent and can be depended on:
the solidity of middle-class institutions

[TahlilGaran] Dictionary of Contemporary English ▲