"quality of being angular," 1640s; see angular + -ity.
Entries linking to angularity
angular adj.
1590s, "having an angle or angles, pointy," from Latin angularis "having corners or angles," from angulus "angle, corner" (see angle (n.)). It is attested earlier in an astrological sense, "occupying a cardinal point of the zodiac" (late 14c.). Angulous "having many corners" is from mid-15c. Angular as "measured by an angle" is from 1670s, hence angular motion "motion of a body which moves around a fixed point."
-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]