1. [adj]  not standard; not accepted as a model of excellence; "a nonstandard text"
2. [adj]  varying from or not adhering to a standard; "nonstandard windows"; "envelopes of nonstandard sizes"; "nonstandard lengths of board"
3. [adj]  (linguistics) not 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

NONSTANDARD is a 11 letter word that starts with N.