1.
na-adjective; adjectival noun (grammar term)
The school-grammar term for words like 静か and きれい, which take な before a noun and だ at the end of a sentence.
Related Words
Related:
語幹 (word stem ( is the stem)
Related:
感嘆詞 (interjection)
Related:
名詞 (noun (part of speech))