Meaning
The kanji 由 (由) is a key character you'll encounter at the JLPT N3 level. It primarily means "reason," "cause," "origin," and "means." When combined with other kanji, it can also express "freedom." Learning 由 is essential for understanding the underlying reasons for events, their origins, and how actions are allowed or accomplished.
Historically, 由 is believed to be an ideogram or a pictograph. One common theory suggests it depicts a sprout pushing its way out of the ground, symbolizing "origin" or "beginning." The outer, box-like structure might represent the ground or a field (like 田, the kanji for 'rice field'), while the vertical line shows something moving upwards, perhaps a conduit. Another theory proposes it represents a tube or funnel, through which something flows or is directed. This interpretation naturally leads to meanings like "means" or "reason." After all, the idea of something flowing from somewhere strongly implies "origin" and "cause."
These visual interpretations offer a subtle connection to its modern meanings. Consider a sprout emerging from the ground: that point is its origin. Similarly, if liquid flows through a pipe or funnel, the pipe acts as the means of travel, and its starting point is the cause. Thus, 由 visually conveys the ideas of a starting point, a channel, and the fundamental basis for something.
由 has just 5 strokes and is introduced to native speakers in the 3rd grade of elementary school. Its simple appearance, however, conceals its versatile and important conceptual role in the Japanese language.
Readings
On'yomi (音読み) — Chinese-derived readings
On'yomi, or Chinese-derived readings, for 由 are typically used when the kanji is part of a compound word, often with other kanji to create more complex meanings. For 由, the main On'yomi is ユ. While ユウ also exists, it's less common in everyday N3 vocabulary.
ユ (YU): ユ is 由's most common On'yomi, appearing in many important vocabulary words. It often contributes to meanings related to reason, origin, or freedom.
理由 (riyū) — meaning "reason" or "motive." This compound is essential for explaining why something happened or the basis for an action.
Example: 試験に合格した理由は努力したからです。
- 自由 (jiyū) — meaning "freedom" or "liberty." This term frequently describes the state of being unconstrained.
Example: 彼女は旅行に行く自由を持っています。
- 由来 (yurai) — meaning "origin," "source," or "history." It describes where something came from or how it began.
Example: このお祭りの由来は古い時代にさかのぼります。
Kun'yomi (訓読み) — Native Japanese readings
Kun'yomi, the native Japanese readings, are used when the kanji appears alone or combines with hiragana to form a Japanese word. For 由, よし is the most notable Kun'yomi, though よる is also listed.
よし (yoshi): This reading is less common in modern everyday speech as a standalone word but is important in understanding certain compounds and classical expressions. It can mean "reason," "means," "story," or "circumstance." While often seen in literary contexts, it also appears in specific fixed phrases.
由無し (yoshinashi) — an adjective meaning "without reason," "pointless," or "trivial." It describes something lacking purpose or sense.
Example: そんな由無し事は気にしないでください。
- よる (yoru): This reading means "to be due to" or "to originate from." In contemporary Japanese, however, it's almost exclusively written with other kanji like 因る or 依る. Although よる is listed for 由, you won't commonly see it used with this specific kanji in isolation or in compounds an N3 learner would regularly encounter. For practical learning, focus on ユ for On'yomi and understanding よし within specific compounds.
Common Words & Compounds
由 appears in many Japanese words, expressing ideas of origin, reason, means, and freedom. Below are some common and useful compounds, grouped by their main theme.
Words related to Reason and Cause
理由 (riyū) — reason, motive, grounds. This is arguably the most common compound using 由.
事由 (jiyū) — circumstances, reason, grounds (often in a formal or legal context).
縁由 (en'yu) — reason, cause, connection, relation (slightly formal or literary).
所以 (yuen) — reason, cause, origin. This is a special, irregular reading, but it’s an important word.
Words related to Origin and History
由来 (yurai) — origin, source, history, derivation. Explains how something came to be.
由緒 (yuisho) — history, pedigree, lineage (often implying respectability or tradition).
発由 (hatsuyu) — originating from, dispatching from (less common, often in formal or administrative contexts).
Words related to Freedom and Means
自由 (jiyū) — freedom, liberty. A key concept in many societies.
経由 (keiyu) — via, by way of, through. Indicates a route or intermediary point.
由無し事 (yoshinashigoto) — a trivial matter, something without a good reason.
不自由 (fujiyū) — inconvenience, disability, lack of freedom. (The opposite of 自由).
Example Sentences
日本で働きたい理由は何ですか。
Nihon de hatarakitai riyū wa nan desu ka?
What is your reason for wanting to work in Japan?
彼は言論の自由を主張しました。
Kare wa genron no jiyū o shuchō shimashita.
He asserted freedom of speech.
このお祭りの由来は古い神話にあります。
Kono omatsuri no yurai wa furui shinwa ni arimasu.
The origin of this festival lies in an ancient myth.
電車は東京駅を経由して横浜へ向かいます。
Densha wa Tōkyō-eki o keiyu shite Yokohama e mukaimasu.
The train goes to Yokohama via Tokyo Station.
新しい法律は人々にさらなる自由を与えました。
Atarashii hōritsu wa hitobito ni saranaru jiyū o ataemashita.
The new law gave people even more freedom.
彼には私に話す由がないと思います。
Kare ni wa watashi ni hanasu yoshi ga nai to omoimasu.
I don't think he has a reason to talk to me.
その事件の所以を調べる必要があります。
Sono jiken no yuen o shiraberu hitsuyō ga arimasu.
We need to investigate the cause of that incident.
この由緒ある家は何百年も前からあります。
Kono yuisho aru ie wa nanbyakunen mo mae kara arimasu.
This venerable house has existed for hundreds of years.
子供たちは公園で自由に遊んでいます。
Kodomo-tachi wa kōen de jiyū ni asonde imasu.
The children are playing freely in the park.
Memory Tip
To remember the kanji 由 (由), you can visualize it as a small "sprout" pushing its way up through a "field" or "box." The outer box-like shape (resembling 田, the kanji for 'field' or 'rice paddies') can be seen as the earth or a container, and the vertical line with a short top stroke represents the plant originating and growing from within. This image directly connects to its meanings of "origin" and "cause" – the reason why the plant exists and its starting point. Alternatively, think of it as a "pipe" or "funnel" (the box with a central channel) through which water or information flows. The water's path is its "means" of travel, and its source is its "origin." If you think of a stream of information, the channel provides the "reason" or "explanation." Imagine a plant growing out of a container: the container is the "field," and the plant's emergence is its "origin" and the "reason" it's there. This simple visual connection helps link the kanji's shape to the abstract concepts of reason, origin, and means.