Japanese symbol for “irreducible”

既約

きやく

Romaji: kiyaku

irreducible

In Japanese, irreducible is 既約, read きやく (kiyaku).

Before using these characters for a tattoo, check them with a native speaker. Dictionary words often have several meanings, and the right choice depends on context.

Meanings

adj-na, adj-no, n irreducible (math)

Kanji and stroke order

既

previously, already, long ago

on: キ
kun: すで.に

10 strokes · JLPT 1

約

promise, approximately, shrink

on: ヤク
kun: つづ.まる、つづ.める、つづま.やか

9 strokes · JLPT 2

Related words

Words that share a kanji.

Word	Reading	Meaning
既に	すでに sudeni	already
既存	きそん kison	existing
既成	きせい kisei	established; existing; accomplished
既婚	きこん kikon	married
既定	きてい kitei	established; fixed; prearranged
契約	けいやく keiyaku	contract; compact; agreement
予約	よやく yoyaku	reservation; appointment; booking
約束	やくそく yakusoku	promise; agreement; arrangement

Data: JMdict (CC BY-SA 4.0); KANJIDIC2 (CC BY-SA 4.0); KanjiVG (CC BY-SA 3.0); wordfreq (CC BY-SA 4.0 (data)). Retrieved 2026-10-22.