- not standard.
- not conforming in pronunciation, grammar, vocabulary, etc., to the usage characteristic of and considered acceptable by most educated native speakers; lacking in social prestige or regionally or socially limited in use: a nonstandard dialect; nonstandard English.
- of or relating to a generalized system of numbers that includes the real numbers but also includes infinite and infinitesimal numbers: nonstandard analysis.
- denoting or characterized by idiom, vocabulary, etc, that is not regarded as correct and acceptable by educated native speakers of a language; not standard
- deviating from a given standard
