"salty character or quality," 1650s; see saline + -ity.
Entries linking to salinity
saline adj.
c. 1500, "made of salt" (a sense now obsolete), probably from Latin salinum "salt cellar" or salinae "salt pits," from sal (genitive salis) "salt" (from PIE root *sal- "salt"). The meaning "of, pertaining to, or characteristic of salt" is by 1771.
Saline solution is attested from 1833. Also in Middle English as a noun meaning "salt pit" (13c.), "a salt spring" (mid-15c.). As a shortening of saline solution, by 1926.
-ity
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]