dull

1 of 2

adjective

ˈdəl 

1

: tedious, uninteresting

dull lectures

2

: lacking sharpness of edge or point

a dull knife

3

a

: not resonant or ringing

a dull booming sound

b

: lacking in force, intensity, or sharpness

a dull ache

4

: lacking brilliance or luster

a dull finish

5

: cloudy

dull weather

6

of a color : low in saturation (see saturation sense 4a) and low in lightness

a dull green

7

: mentally slow : stupid

8

a

: slow in perception or sensibility : insensible

somewhat dull of hearing

dull to what went on about her

—Willa Cather

b

: lacking zest (see zest sense 2) or vivacity : listless

a dull performance

9

: slow in action : sluggish

dull markets

dullness noun

or less commonly dulness

ˈdəl-nəs 

dully

ˈdə(l)-lē 

adverb

dull

2 of 2

verb

dulled; dulling; dulls

transitive verb

: to make dull

dull a knife's edge

intransitive verb

: to become dull

The blade dulled with use.

Synonyms

Adjective

• blunt
• blunted
• dulled

Verb

• blunt
• reduce
• damp
• deaden
• numb
• diminish
• dampen
• weaken
• benumb

Choose the Right Synonym for dull

dull, blunt, obtuse mean not sharp, keen, or acute.

dull suggests a lack or loss of keenness, zest, or pungency.

a dull pain

a dull mind

blunt suggests an inherent lack of sharpness or quickness of feeling or perception.

a person of blunt sensibility

obtuse implies such bluntness as makes one insensitive in perception or imagination.

too obtuse to take the hint

synonyms see in addition stupid

Examples of dull in a Sentence

Adjective

the dull roar of the crowd

the dull knife just bounced off the skin of the tomato without cutting it

Verb

Fog dulled the morning sunlight.

Special earplugs dulled the sound of the chain saw.

His hair dulled as he aged.

The dog's eyes dulled as he got sick.

She takes medicine to dull the pain.

Fear dulled his need for adventure.

The knife was dulled from use.

The blade should be replaced as soon as it dulls.

Recent Examples on the Web

Adjective

And what often emerges instead is a dull kind of numbness, chronic irritability or total withdrawal. —Mark Travers, Forbes.com, 25 June 2025

Get rid of dull and dirty razor heads (which should no longer be used) and pair your bathing supplies down to only the items that are used on a weekly basis. —Abigail Wilt, Southern Living, 20 June 2025

Verb

Even when exhaustion dulled my vigilance, my worries didn’t disappear. —David Litt june 25, Literary Hub, 25 June 2025

The trade-off with vertical slots is that the tip of your blades will rest up against the block material and may dull over time. —Bestreviews, Chicago Tribune, 13 June 2025

Word History

Etymology

Adjective and Verb

Middle English dul; akin to Old English dol foolish, Old Irish dall blind

First Known Use

Adjective

13th century, in the meaning defined at sense 7

Verb

13th century, in the meaning defined at transitive sense

Phrases Containing dull

• (as) dull as dishwater
• (as) dull as ditchwater
• dull-witted
• never a dull moment

Rhymes for dull

• cull
• gul
• gull
• lull
• ndebele
• null
• scull
• skull
• stull
• trull
• tulle
• seagull

Kids Definition

dull

1 of 2 adjective

ˈdəl 

1

: mentally slow : stupid

2

: listless

3

: slow in action : sluggish

4

: lacking sharpness of edge or point

5

: lacking brilliance or luster

6

: not ringing, sharp, or intense

a dull roar

7

: cloudy sense 2, overcast

8

: tedious, uninteresting

a dull lecture

9

: slightly grayish

a dull blue

dullness noun

also dulness

ˈdəl-nəs 

dully

ˈdəl-(l)ē 

adverb

dull

2 of 2 verb

: to make or become dull

Medical Definition

dull

adjective

ˈdəl 

1

: mentally slow or stupid

2

: slow in perception or sensibility

3

: lacking sharpness of edge or point

a dull scalpel

4

: lacking in force, intensity, or acuteness

a dull pain

dull verb

dullness noun

or dulness

ˈdəl-nəs 

dully

ˈdəl-ē 

adverb