Japanese symbol for “quadratic”

二次

にじ

Romaji: niji

second

In Japanese, quadratic is 二次, read にじ (niji).

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-no, n second
adj-f secondary
adj-f quadratic (function, equation, etc.); second-order (math)
adj-no fictional (in relation to anime, manga, etc.); drawn; two-dimensional

Written forms: 二次、２次、虹. Readings: にじ.

Kanji and stroke order

二

two, two radical (no. 7)

on: ニ、ジ
kun: ふた、ふた.つ、ふたたび

2 strokes · JLPT 4

次

next, order, sequence

on: ジ、シ
kun: つ.ぐ、つぎ

6 strokes · JLPT 2

Related words

Words that share a kanji.

Word	Reading	Meaning
二つ	ふたつ futatsu	two
二宮	にぐう niguu	the Two Ise Shrines
二塁打	にるいだ niruida	two-base hit; double
二塁	にるい nirui	second base
二分	にぶん nibun	halving; dividing (into two parts); bisection
一石二鳥	いっせきにちょう issekinichou	killing two birds with one stone
次元	じげん jigen	dimension
次回	じかい jikai	next time (occasion)

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.