non-gradable
adjective language specialized uk/ˌnɒnˈɡreɪ.də.bəl/ us/ˌnɑːnˈɡreɪ.də.bəl/
（形容词或副词）非等级的
A non-gradable adjective or adverb is one that cannot be used in the comparative or superlative, or that cannot be qualified by words such as 'very' or 'quite'.