Noun of poor

poor means "poor, impoverished; pitiable, pitiful," and is an adjective whose noun form is poverty. poverty is a noun meaning poor, lacking, insufficient, short, lacking, small. insufficiency, shortage, lack, small amount.

Adjectives and nouns are two grammatically different word forms. An adjective is used to modify a noun or other lexical word, and it serves to describe or qualify the word being modified.