The word 诺言 is formed by combining two characters, each contributing a layer of meaning to create a new, unified concept. The first character, 诺 (nuò), carries the core idea of assent, agreement, or a pledge. The second, 言 (yán), simply means words or speech. They are fused not by grammar, but by a conceptual blend: the specific type of speech (諾) is identified and then categorized by the general concept of spoken words (言). Together, they crystallize into the abstract noun meaning "a promise", literally, the "words of assent" or "pledge-speech", where the whole becomes a single entity denoting a solemn verbal commitment.