idiolect
n. a dialect spoken at the level of an individual. In one sense, all speakers have an idiolect because no two people use their native language in the same way. In another, the term is reserved for the most idiosyncratic forms of personal language use, especially those involving eccentricities of construction or vocabulary. An idiolect of this kind may be developed by a person who acquires a second language unsystematically, especially if this occurs in an unusual or isolated learning environment (see interlanguage; fossilization). Some poets and writers also develop distinctive idiolects in their writings. —idiolectal
adj.