hybridity n.

c. 1600, "offspring of plants or animals of different variety or species," from Latin hybrida, variant of ibrida "mongrel," specifically "offspring of a tame sow and a wild boar," of unknown origin but probably from Greek and somehow related to hubris. A rare word before the general sense "anything a product of two heterogeneous things" emerged c. 1850. The adjective is attested from 1716. As a noun meaning "automobile powered by an engine that uses both electricity and gasoline," 2002, short for hybrid vehicle, etc.

word-forming element making abstract nouns from adjectives and meaning "condition or quality of being ______," from Middle English -ite, from Old French -ete (Modern French -ité) and directly from Latin -itatem (nominative -itas), suffix denoting state or condition, composed of -i- (from the stem or else a connective) + the common abstract suffix -tas (see -ty (2)).

Roughly, the word in -ity usually means the quality of being what the adjective describes, or concretely an instance of the quality, or collectively all the instances; & the word in -ism means the disposition, or collectively all those who feel it. [Fowler]