(of an adjective) Describing a quality that cannot normally be varied because it is extreme (e.g. freezing), absolute (e.g. dead), or classification (e.g. nuclear).
noun
Any adjective that is not gradable.
noncomparable
adj
Not comparable.
How often have the words non-gradable and noncomparable occurred in a corpus of books? (source: Google Ngram Viewer )