Entries linking to lethality
"causing or resulting in death," 1580s, from Late Latin lethalis, alteration of Latin letalis "deadly, fatal," from lethum/letum "death," a word of uncertain origin. According to de Vaan, from Proto-Italic *leto-, which is perhaps a noun from a PIE past participle of a verb meaning "let, let go," on the notion of death as "a letting go." If so, related to Old Church Slavonic leto "summer, year" (from notion of "going"), Russian leto "summer," (pl.) "age, years;" Russian let' (archaic) "it is possible, allowed;" Old Norse lað, Old English læð "land," Gothic unleds "poor." The form altered in Late Latin by association with lethes hydor "water of oblivion" in Hades in Greek mythology, from Greek lethe "forgetfulness" (see Lethe).
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]
updated on June 16, 2016