Meaning
The kanji 流 (なが.れる, なが.す, リュウ) primarily conveys the meaning of 'flow' or 'current'. It's a versatile character, used to describe the movement of liquids, air, time, or even abstract concepts like trends and styles. At its core, 流 depicts dynamic, continuous movement, often effortlessly, from one point to another.
Its origin is deeply connected to water. Notice the left-hand side of the character: the radical 氵 (さんずい - sanzui), which is a variant of 水 (みず - water). This radical immediately signals a connection to water and its associated actions. While more complex in its ancient origins, the right side of the character visually suggests water flowing, perhaps over a surface or through a channel. This combination powerfully evokes the image of a stream or current, emphasizing movement and direction. With 10 strokes, it's taught in the 3rd grade, making it a relatively early kanji for Japanese learners. Understanding the water radical is key to grasping its fundamental meaning.
Readings
On'yomi (音読み) — Chinese-derived readings
The primary on'yomi reading for 流 is リュウ (ryū), derived from its historical Chinese pronunciation. You'll frequently encounter this reading in compound words, especially those relating to general concepts of flow, current, or specific styles and schools of thought.
流行 (ryūkō) — This means 'fashion,' 'trend,' or 'epidemic.' It describes something that is 'flowing' or spreading widely among people. For example, 新しい髪型が流行している (Atarashii kamigata ga ryūkō shiteiru - A new hairstyle is in fashion) or 新型インフルエンザが流行している (Shingata infuruenza ga ryūkō shiteiru - A new type of influenza is spreading).
交流 (kōryū) — Meaning 'exchange,' 'interaction,' or 'alternating current.' It literally implies a 'crossing flow,' indicating communication or movement between two entities. For instance, 文化交流 (bunka kōryū - cultural exchange) or 国際交流パーティー (kokusai kōryū pātī - international exchange party).
一流 (ichiryū) — Translates to 'first-class,' 'top-grade,' or 'leading.' Here, 流 signifies a 'stream' or 'school,' suggesting someone or something belonging to the highest tier or standard. Like 一流の料理人 (ichiryū no ryōrinin - a first-class chef) or 彼は一流の大学を卒業した (Kare wa ichiryū no daigaku o sotsugyō shita - He graduated from a top-tier university).
Kun'yomi (訓読み) — Native Japanese readings
The kun'yomi readings are なが.れる (naga.reru) and なが.す (naga.su), which are native Japanese verbs. They represent the actions of 'flowing' (intransitive) and 'to let flow' or 'to shed' (transitive), respectively.
なが.れる (naga.reru) — This is an intransitive verb meaning 'to flow,' 'to stream,' 'to be washed away,' or 'to pass (of time).' It describes a natural or automatic movement. For example, 涙が流れる (namida ga nagareru - tears flow) or 時間が流れるのは早いものだ (jikan ga nagareru no wa hayai mono da - time really flies).
なが.す (naga.su) — This is a transitive verb meaning 'to let flow,' 'to drain,' 'to wash away,' 'to shed,' or 'to broadcast.' It implies someone or something intentionally causing something to flow. For instance, 水を流す (mizu o nagasu - to flush water) or 音楽を流す (ongaku o nagasu - to play music/broadcast music). You might also hear 汗を流す (ase o nagasu - to shed sweat) when talking about hard work.
Common Words & Compounds
The kanji 流 forms part of many common and essential Japanese words. Here are some categorized examples showcasing its diverse usage:
Movement and Direction
流星 (ryūsei) — meteor, shooting star. (Literally: 'flowing star')
合流 (gōryū) — confluence, merging, joining (e.g., rivers, roads, or groups). (Literally: 'joining flow')
漂流 (hyōryū) — drifting, afloat. (Literally: 'floating flow')
主流 (shuryū) — mainstream, main current. (Literally: 'main flow')
急流 (kyūryū) — rapid stream, torrent. (Literally: 'urgent flow')
Style and Method
流儀 (ryūgi) — style, manner, way. (Literally: 'flow method')
流派 (ryūha) — school (of thought), sect, denomination. (Literally: 'flow faction')
流暢 (ryūchō) — fluent, smooth. (Describes speech or movement that flows well)
自己流 (jikoryū) — one's own style, self-taught. (Literally: 'self flow')
Abstract and Other Concepts
電流 (denryū) — electric current. (Literally: 'electric flow')
流域 (ryūiki) — river basin, drainage area. (Literally: 'flow area')
暖流 (danryū) — warm current (oceanography). (Literally: 'warm flow')
寒流 (kanryū) — cold current (oceanography). (Literally: 'cold flow')
Example Sentences
川の水が静かに流れる。
Kawa no mizu ga shizuka ni nagareru.
The river water flows quietly.
時間は早く流れるものだ。
Jikan wa hayaku nagareru mono da.
Time flows quickly.
古い慣習は次第に流れていく。
Furui kanshū wa shidai ni nagarete iku.
Old customs gradually fade away (flow away).
音楽を流しながら勉強する。
Ongaku o nagashi nagara benkyō suru.
I study while playing music.
涙を流して悲しんだ。
Namida o nagashite kanashinda.
I shed tears and grieved.
この地域では新しい文化が流れてきた。
Kono chiiki dewa atarashii bunka ga nagarete kita.
New culture has flowed into this region.
彼は自分の流儀で仕事をする。
Kare wa jibun no ryūgi de shigoto o suru.
He does his work in his own style.
世界中で流行している歌だ。
Sekaichū de ryūkō shiteiru uta da.
It's a song that's popular (flowing around) all over the world.
汗を流して一生懸命働いた。
Ase o nagashite isshōkenmei hataraita.
I worked hard, shedding sweat.
Memory Tip
To remember the kanji 流, focus on its components. The left side is the 'water' radical (氵), a clear visual cue—imagine a three-pronged splash or drops of water. The right side can be thought of as a stylized representation of something in motion or flowing. Picture water flowing around an object or through a winding path. When you see the water radical combined with the motion on the right, it naturally suggests the idea of 'flow' or 'current.' You might think of a river (氵) flowing downstream, carrying everything with it. The 10 strokes can be visualized as the continuous movement characteristic of flowing water.