"quality or state of being discontinuous, interrupted condition," 1560s, from Medieval Latin discontinuus, from discontinuare (see discontinue) + -ity.
Entries linking to discontinuity
discontinue v.
late 14c., discontinuen, "be interrupted, cease, stop," from Old French discontinuer (14c.), from Medieval Latin discontinuare "discontinue," from dis- "not" (see dis-) + Latin continuare "to continue" (see continue). Transitive sense "cause to cease" is from late 15c. Related: Discontinued; discontinuity; discontinuous; discontinuation.
-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]