副詞
ふくし · fukushi · JLPT N2 · noun
adverb
副 = secondary + 詞 = word: a secondary word that modifies verbs
副 means secondary or auxiliary, and 詞 means word. An adverb is a secondary word: it adds how, when, or how much to a verb, adjective, or other adverb.
副 — 刀 knife + 畐 (full vessel, phonetic)
A semantic-phonetic compound. The knife radical 刂 (刀) suggests cutting or splitting, while 畐 (a full jar) gives the sound. The original sense was 'to split in two,' which extended to 'secondary' or 'deputy' — something paired alongside the main one.