quasi-adjective

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun adjectival noun, a specific Japanese part of speech. Some of these words can be used as regular nouns, and all can be used as adjectives when followed by the postfix な (na), in contrast to Japanese common adjectives, 形容詞 (keiyōshi). In Japanese grammar, these words are categorized as 形容動詞 (keiyōdōshi).