Words related to -ism
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]
"practice or habit of being absent," 1822, from absentee + -ism; originally in reference to landlords, especially in Ireland, who lived at a distance from their estates (the earlier word was absenteeship (1778) and Johnson's dictionary has absentee in the landlord sense). In reference to pupils or workers from 1922.