nonstandard

Definitions

Not conforming to a standard, rule, or accepted model.

Relating to language usage that deviates from the established norms of grammar, spelling, or pronunciation.

Examples

The professor marked the essay down for its use of nonstandard grammar and informal slang.

Using nonstandard parts to repair the engine may void the manufacturer's warranty.

Synonyms

irregular unconventional atypical abnormal unorthodox anomalous informal

Antonyms

standard conventional normal regular typical orthodox formal