Meaning
拡 means to expand, enlarge, spread, or widen — pushing something outward beyond its current bounds. That something can be physical (a road, a building), organizational (a company, a network), or abstract (influence, a sound wave, information). News articles, business reports, and academic texts all rely on this kanji, making it a genuine N2 workhorse.
Structurally, 拡 has two elements: the left radical ⺘ (てへん, the hand radical, a simplified 手), and the phonetic component 広 on the right. The hand radical points to a physical act — pushing or stretching outward with the hands. 広 independently means "wide" or "broad," lending both a phonetic hint (the カク sound) and the sense of breadth. Put them together: hands stretching something wide — the act of expansion made visible.
拡 is the simplified form of the traditional character 擴, keeping the same hand radical but a streamlined right side. A Joyo kanji assigned at the junior-high level, it has 8 strokes. Its Hán-Việt reading is KHOÁCH.
Readings
On'yomi (音読み) — Chinese-derived readings
カク is the only on'yomi. Nearly every compound with 拡 uses this reading — it's the one to prioritize.
- 拡大 (kakudai) — enlargement, expansion, magnification. Works for zooming into a photo, growing a company, or blowing up a diagram.
- 拡張 (kakuchō) — extension, expansion. Appears in computing (browser extensions, memory upgrades) and urban planning (road widening, territorial growth).
- 拡散 (kakusan) — diffusion, spread, proliferation. Covers light scattering in physics, viral posts on social media, and nuclear proliferation in geopolitics.
- 拡充 (kakujū) — expansion and improvement. Used when an organization grows and upgrades simultaneously, not just gets bigger.
- 拡声 (kakusei) — sound amplification, as in 拡声器 (kakuseiki) — loudspeaker, megaphone.
Kun'yomi (訓読み) — Native Japanese readings
The two kun'yomi — ひろ(げる) and ひろ(まる) — share the same ひろ root as 広 (wide). They form a transitive-intransitive pair, a classic Japanese verb pattern.
- 拡げる (hirogeru) — to spread out, open up, expand (transitive). Spreading a map on a table, opening a business into a new market, throwing your arms wide.
- 拡まる (hiromaru) — to spread, become widespread (intransitive). A rumor that takes on a life of its own, a trend that catches across the country.
Common Words & Compounds
拡 shows up across registers — everyday speech, business writing, technology, and news. Key compounds by theme:
Size & Scale:
- 拡大 (kakudai) — enlargement, expansion, magnification
- 拡大鏡 (kakudaikyō) — magnifying glass, loupe
- 拡大解釈 (kakudai kaishaku) — broad or liberal interpretation of a rule or law
Growth & Development:
- 拡張 (kakuchō) — expansion, extension (territory, network, software)
- 拡充 (kakujū) — expansion and enhancement of facilities or services
- 軍拡 (gunkaku) — military buildup, arms expansion
Spread & Diffusion:
- 拡散 (kakusan) — diffusion, spread, proliferation
- 核拡散 (kaku kakusan) — nuclear proliferation
- 情報拡散 (jōhō kakusan) — viral spread of information
Sound & Broadcasting:
- 拡声器 (kakuseiki) — loudspeaker, megaphone, public address system
Width & Space:
- 拡幅 (kakufuku) — road or pathway widening
- 拡張現実 (kakuchō genjitsu) — augmented reality (AR)
Example Sentences
会社は海外に事業を拡大する計画だ。
Kaisha wa kaigai ni jigyō wo kakudai suru keikaku da.
The company plans to expand its business overseas.
地図を拡げて、目的地を確認した。
Chizu wo hirogete, mokutekichi wo kakunin shita.
I spread out the map and confirmed the destination.
SNSで噂が急速に拡まった。
SNS de uwasa ga kyūsoku ni hiromatta.
The rumor spread rapidly on social media.
拡散防止のため、外出を控えるよう呼びかけた。
Kakusan bōshi no tame, gaishutsu wo hikaeru yō yobikaketa.
They urged people to refrain from going out in order to prevent the spread.
拡大鏡で小さな文字を読んだ。
Kakudaikyō de chiisana moji wo yonda.
I read the small text using a magnifying glass.
政府は教育予算の拡充を約束した。
Seifu wa kyōiku yosan no kakujū wo yakusoku shita.
The government promised to expand and improve the education budget.
道路の拡幅工事が来月から始まる。
Dōro no kakufuku kōji ga raigetsu kara hajimaru.
Road widening construction will begin next month.
拡張現実の技術は医療の分野でも使われている。
Kakuchō genjitsu no gijutsu wa iryō no bunya demo tsukawarete iru.
Augmented reality technology is also being used in the medical field.
彼は人脈を拡げるために積極的に交流している。
Kare wa jinmyaku wo hirogeru tame ni sekkyokuteki ni kōryū shite iru.
He actively socializes in order to expand his network of connections.
Memory Tip
Picture hands (⺘) grabbing the edges of something wide (広) and pulling hard — stretching it wider still. Left side: hand radical. Right side: already means "wide." Together: expand. When 拡 appears in a compound, those hands are at work — a company pushing into new markets, a rumor going viral, a lens making tiny print readable.
Vietnamese learners: KHOÁCH sounds close to "khoác" (to drape or spread something over) — a useful extra hook.