-ity

Etymology

Latin via Old French

Suffix

1. Used in forming a noun to represent the property corresponding to an adjective, for example, prolix -> prolixity (the property of being prolix), triangular -> triangularity (the property of being triangular).

Usage notes

1. Not all adjectives are converted to nouns by using this suffix, thus compare with
   • -ness, as in redness , not redity
   • -ism, as in agnosticism
   • -ion , as in abstraction