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 individualinterpretation of the value of the intrinsic qualities of the noun that has been adjectivified.
(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.)
the word "savage" is the only word that is considered a nounjective
Noun: bruh... look at that savage
Adjective: bruh... I can't believe Zach is that savage, did he really just do that