Open English Wordnet
Adjectives
(a)nonstandardnot conforming to the language usage of a prestige group within a community“a nonstandard dialect is one used by uneducated speakers or socially disfavored groups”, “the common core of nonstandard words and phrases in folk speech” (A.R.Dunlap)
(a)nonstandardvarying from or not adhering to a standard“nonstandard windows”, “envelopes of nonstandard sizes”, “nonstandard lengths of board”