Meaning
The kanji 副 (ふく) primarily conveys meanings related to being secondary, supplementary, or subordinate. Its primary interpretations include 'deputy,' 'vice-,' 'assistant,' 'associate,' 'side,' 'secondary,' and 'copy.' You'll often see this kanji in official titles, administrative settings, and whenever something is described as non-primary or supplementary.
副 (fuku) is a phono-semantic compound. The left component, 畐 (fú in Chinese), acts as a phonetic element here, pronounced 'fuku.' Originally, it depicted a jar or bottle, implying 'fullness' or 'abundance.' In this context, 畐 often suggests something 'extra' or 'additional.' The right component is the radical 刀 (かたな), meaning 'knife' or 'sword.'
When combined, the 刀 radical might suggest 'cutting,' 'dividing,' or 'splitting off' from something full or whole. This visual hint suggests something 'separated' or 'added' to a main entity, leading to meanings like 'secondary,' 'subordinate,' or 'assistant.' Think of it as an 'extra' (畐) blade (刀) for support or to divide tasks.
With 11 strokes, 副 is a Jōyō kanji, meaning it's designated for general use. Students typically learn it in secondary education (junior high or high school), which roughly corresponds to an N2 level on the JLPT.
Readings
On'yomi (音読み) — Chinese-derived readings
The primary, and almost exclusive, on'yomi reading for 副 is フク (fuku). You'll find this reading in nearly all compound words containing 副, particularly when it functions as a prefix to denote 'deputy,' 'vice-,' 'assistant,' 'secondary,' or 'copy.'
副社長 (fukushachō) — This compound refers to a company's vice president or executive vice president. Here, 副 (fuku) means 'vice' or 'deputy,' combining with 社長 (shachō), which means 'company president.'
副作用 (fukusayō) — Meaning 'side effect,' this term is commonly used in medicine or when discussing unintended consequences. 副 (fuku) indicates 'side' or 'secondary,' while 作用 (sayō) means 'action' or 'effect.'
副収入 (fukushūnyū) — This refers to a secondary income or side income. 副 (fuku) means 'secondary,' and 収入 (shūnyū) means 'income.'
Kun'yomi (訓読み) — Native Japanese readings
The kanji 副 does not have any commonly used kun'yomi (native Japanese) readings. In practical Japanese, especially from the N2 level onwards, you'll almost exclusively encounter this kanji with its on'yomi reading, フク (fuku), primarily within compound words. It's not typically used as a standalone word with a native Japanese reading.
Common Words & Compounds
The kanji 副 appears in numerous compound words across various categories, often indicating a secondary, assisting, or subordinate role. It's a highly productive kanji.
Official Titles & Positions:
副社長 (fukushachō) — Vice president (of a company)
副大臣 (fukudaijin) — Vice minister (in government)
副委員長 (fukuiinchō) — Vice chairman
副操縦士 (fukusōjūshi) — Co-pilot
副業 (fukugyō) — Side job, second job, sideline
Secondary & Supplementary Aspects:
副作用 (fukusayō) — Side effect
副収入 (fukushūnyū) — Secondary income, side income
副読本 (fukudokuhon) — Supplementary reader, sub-textbook
副菜 (fukusai) — Side dish (in a meal)
副産物 (fukusanbutsu) — Byproduct
Copies & Grammar:
副本 (fukuhon) — Duplicate, copy (of a document)
副詞 (fukushi) — Adverb (grammatical term, literally 'secondary word')
副賞 (fukushō) — Supplementary prize, extra prize
副音声 (fukuonsei) — Secondary audio (e.g., a commentary track on TV)
Example Sentences
彼は会社の副社長として重要な役割を担っています。
Kare wa kaisha no fukushachō to shite jūyō na yakuwari o ninatte imasu.
He plays an important role as the company's vice president.
この薬には眠気という副作用があります。
Kono kusuri ni wa nemuke to iu fukusayō ga arimasu.
This medicine has a side effect of drowsiness.
彼は本業の傍ら、副業でフリーランスの仕事もしています。
Kare wa hongyō no katawara, fukugyō de furiiransu no shigoto mo shite imasu.
Aside from his main job, he also does freelance work as a side job.
健康的な食事には、主菜の他に副菜をバランス良く摂ることが大切です。
Kenkōteki na shokuji ni wa, shusai no hoka ni fukusai o baransu yoku toru koto ga taisetsu desu.
For a healthy diet, it's important to have a good balance of side dishes in addition to the main dish.
飛行機事故の際、副操縦士が冷静に対応しました。
Hikōki jiko no sai, fukusōjūshi ga reisei ni taiō shimashita.
During the plane accident, the co-pilot responded calmly.
この教科書には、理解を深めるための副読本が付属しています。
Kono kyōkasho ni wa, rikai o fukameru tame no fukudokuhon ga fuzoku shite imasu.
This textbook comes with a supplementary reader to deepen understanding.
マラソン大会の優勝者にはメダルと高額な副賞が贈られました。
Marason taikai no yūshōsha ni wa medaru to kōgaku na fukushō ga okurareta.
The winner of the marathon received a medal and a valuable supplementary prize.
テレビ番組では、日本語と英語の副音声を選ぶことができます。
Terebi bangumi de wa, nihongo to eigo no fukuonsei o erabu koto ga dekimasu.
On this TV program, you can choose between Japanese and English secondary audio.
Memory Tip
To remember 副, visualize its components: the left part 畐 (which can resemble a full container or even a 'rich' person, hinting at abundance or a main role) and the right part 刀 (a knife). Imagine a main leader in a 'full' position. The knife is then used to 'cut off' or delegate some duties to a secondary person. In this way, the 'knife' helps create a 'secondary' or 'assistant' role from the 'full' set of responsibilities. Alternatively, picture a 'full' (畐) set of tools where one 'knife' (刀) acts as an 'extra' or 'secondary' tool for support. This imagery helps connect the components to meanings like 'deputy,' 'assistant,' or 'side.'