-ity

• IPA^(key): [ɪti]; but see the usage notes below

Borrowed from French -ité, from Middle French -ité, from Old French -ete, -eteit (“-ity”), from Latin -itātem, from -itās, from Proto-Indo-European *-it- (suffix). Cognate with Gothic -𐌹𐌸𐌰 (-iþa, “-th”), Old High German -ida (“-th”), Old English -þo, -þu, -þ (“-th”). More at -th.

• -ty
• ⠰⠽

-ity

1. Used to form a noun from an adjective; especially, to form the noun referring to the state, property, or quality of conforming to the adjective's description.
2. Used to form other nouns, especially abstract nouns.

• Many nouns formed with -ity are uncountable; those that are countable form their plurals in -ities.
• The addition of -ity to an adjective results in a shift of stress to the antepenultimate syllable; that is, words in -ity are stressed on the last syllable before the -ity, even in cases where this syllable is part of another suffix (as in words in -ability and -icity). Further, this shift typically results in a change in vowel quality; compare, for example, real and reality, where the sound [æ] in the second word is not present in the first. These vowel quality changes are usually consistent with the spelling of both forms — note that the letter <a> in the second word is present in the first — but sometimes spelling changes are seen, as with the suffix -ous, which when it combines with -ity produces the suffix -osity.
• While a final -c is pronounced [k], before -ity it becomes [s]; compare, for example, elastic and elasticity.
• Final -e is dropped before adding this suffix.

• -ability, -ibility

• -ness, -hood, -ship, -itas, -itude, -th, -ia, -itia, -ability, -ibility, -icity, -osity, -ous, -ose

See -ety

-ity

1. Alternative form of -ety

   ‎hip + ‎-ity → ‎hippity, hippity-hop