鈍(にぶ)い

にぶい

i-adjective

dull; blunt; slow; dim

Conjugation

	Affirmative	Negative
Present	鈍(にぶ)い	鈍(にぶ)くない
Past	鈍(にぶ)かった	鈍(にぶ)くなかった
て form	鈍(にぶ)くて	鈍(にぶ)くなくて
Adverbial	鈍(にぶ)く	—
Conditional ば	鈍(にぶ)ければ	鈍(にぶ)くなければ
Conditional たら	鈍(にぶ)かったら	鈍(にぶ)くなかったら

1. dull; blunt

Not sharp, as of a blade or edge.

この包丁(ほうちょう)は鈍(にぶ)くなった。

This kitchen knife has become dull.

鈍(にぶ)い刃(は)では切(き)れない。

You can't cut with a dull blade.

鈍(にぶ)いナイフで肉(にく)を切(き)るのは大変(たいへん)だ。

It's tough to cut meat with a blunt knife.

2. slow; sluggish; dim-witted

Lacking quickness of perception or response.

彼(かれ)は反応(はんのう)が鈍(にぶ)い。

He is slow to react.

彼(かれ)は感覚(かんかく)が鈍(にぶ)い。

He has dull senses.

寝不足(ねぶそく)で頭(あたま)の回転(かいてん)が鈍(にぶ)くなった。

My thinking became sluggish from lack of sleep.

3. dull; muted (color, sound, pain)

Not bright, clear, or intense.

鈍(にぶ)い痛(いた)みが続(つづ)いている。

A dull pain continues.

鈍(にぶ)い光(ひかり)が窓(まど)から差(さ)し込(こ)んでいた。

A dim light was coming in through the window.

鈍(にぶ)い音(おと)がして、何(なに)かが落(お)ちたようだ。

There was a dull sound, and it seemed like something fell.

鈍(にぶ)い is an i-adjective describing dullness in various contexts: physical sharpness, mental quickness, or intensity.

Forms

Adverbial: 鈍(にぶ)く
Noun form: 鈍(にぶ)さ (dullness)

Common patterns

刃(は)が鈍(にぶ)い (blade is dull)
反応(はんのう)が鈍(にぶ)い (slow reaction)
勘(かん)が鈍(にぶ)い (poor intuition)
鈍(にぶ)い色(いろ) (dull color)
鈍(にぶ)い痛(いた)み (dull pain)

Similar words

鋭(するど)い: Sharp, keen (opposite in all senses)
鈍(にぶ)い vs. 遅(おそ)い: 鈍(にぶ)い implies sluggishness or lack of sharpness, while 遅(おそ)い simply means slow (speed or timing).

Register: Neutral. Can be critical when applied to people (calling someone 鈍(にぶ)い is somewhat rude).

Related Words

Antonym: 鋭(するど)い (sharp, keen)

Related: 鈍重(どんじゅう) (dull, slow, sluggish)

Compare: どんくさい (clumsy, slow-witted, awkward)

Antonym: 鋭利(えいり) (sharp)

Compare: 間(ま)の抜(ぬ)けた (foolish)

general

Added 2026.1.13 15:25 · Revised 2026.9.2 12:02

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