English

insolidity

From in- + solidity.

Proto-Indo-European *h₁én ‘in’

Proto-Germanic *in ‘into’

English in-

Proto-Indo-European *solh₂- ‘integrate, whole’

…

Proto-Italic *soliðos

Latin solidus ‘dense, solid, not hollow’

Latin soliditās

Middle French solidité

Today it means

noun Lack of solidity; weakness.

Language periods are conventional ranges, not dates for this word.

Etymograph / insolidity