What is a radical?
Every kanji is built from smaller components. Radicals (bushu) are the primary components used to categorise kanji in dictionaries. Traditional Japanese dictionaries organise thousands of characters by their radical — once you know which radical a kanji contains, you can find it in any dictionary.
There are 214 traditional radicals derived from the Kangxi dictionary (1716), though modern dictionaries sometimes use simplified systems. You don't need to memorise all 214 — the most frequent 50 or so will help you navigate the vast majority of kanji you'll encounter.
Radicals as meaning clues
Many radicals hint at the meaning of the kanji that contain them. The water radical (氵, a simplified form of 水) appears in kanji related to water and liquids: 海 (sea), 川 (river), 泳 (swim), 湖 (lake), 浴 (bath). The person radical (亻, from 人) appears in kanji related to people and human actions: 休 (rest), 仕 (serve), 働 (work).
This is not a perfect system — many kanji have radicals that no longer reflect their current meaning after centuries of evolution. But even an approximate meaning clue is a useful memory hook.
The most useful radicals to learn first: 人 (person), 口 (mouth), 日 (sun/day), 月 (moon/month), 木 (tree), 水 (water), 火 (fire), 土 (earth), 山 (mountain), 心 (heart). These ten appear in hundreds of common kanji.
Radicals in practice: looking up unknown kanji
Before digital tools, the only way to look up an unknown kanji was to count its strokes or identify its radical. Even today, knowing radicals speeds up digital input — many Japanese IME systems let you search by radical. When you encounter a kanji you can't read, identifying its main component gives you a starting point for any dictionary search.
See kanji in context
Our kanji reference pages show readings, meanings, and cultural notes.