A formal or dummy noun that carries little lexical meaning on its own but serves grammatical functions (e.g., nominalizing or acting as an expletive); in Japanese, words like 'koto' or 'mono' can function this way.
日本語の『こと』は、動詞句を名詞化する形式名詞としてよく使われる。
Japanese 'koto' is often used as a formal noun to nominalize verb phrases.
形式名詞は意味よりも文の構造上の役割が重要な場合が多い。
Formal nouns often serve more of a structural role in a sentence than a semantic one.