A noun in the place of an adjective, in an attempt to ascribe similar qualities to the
object that you use the nounjective in relation to.
Nounjectives suffer from the possibility of making little to no sense, and relying heavily upon
individual interpretation of the
value of the intrinsic qualities of the noun that has been adjectivified.
Andrew: Hey
man, have you heard the latest
Opeth album? That shit is jacket!"
Daniel: Nice use of a nounjective!
"Jacket", in this case, is the nounjective.
(This example suffers from the ambiguous nature of the subjective value of the jacket's usefulness, however, once being told that Andrew is a fan of
Opeth, it becomes apparent that "jacket", in this circumstance, implies a positive outlook.)