dull

American  

[duhl] / dʌl /

adjective

duller, dullest

1. not sharp; blunt.

   a dull knife.

   Antonyms:

   keen, sharp

2. causing boredom; tedious; uninteresting.

   a dull sermon.

   Synonyms:

   vapid, dreary, tiresome, boring

   Antonyms:

   interesting

3. not lively or spirited; listless.

   Synonyms:

   inert, inactive, torpid, apathetic

4. not bright, intense, or clear; dim.

   a dull day; a dull sound.

5. having very little depth of color; lacking in richness or intensity of color.

6. slow in motion or action; not brisk; sluggish.

   a dull day in the stock market.

7. mentally slow; lacking brightness of mind; somewhat stupid; obtuse.

   Synonyms:

   stolid, unintelligent, unimaginative

   Antonyms:

   bright

8. lacking keenness of perception in the senses or feelings; insensible; unfeeling.

9. not intense or acute.

   a dull pain.

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verb (used with or without object)

1. to make or become dull.

   Synonyms:

   benumb, deaden, blunt, discourage, dishearten, depress

dull British  

/ dʌl /

adjective

1. slow to think or understand; stupid

2. lacking in interest

3. lacking in perception or the ability to respond; insensitive

4. lacking sharpness; blunt

5. not acute, intense, or piercing

6. (of weather) not bright or clear; cloudy

7. not active, busy, or brisk

8. lacking in spirit or animation; listless

9. (of colour) lacking brilliance or brightness; sombre

10. not loud or clear; muffled

11. med (of sound elicited by percussion, esp of the chest) not resonant

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verb

1. to make or become dull

dull Idioms  

More idioms and phrases containing dull

• never a dull moment

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Related Words

Dull, blunt refer to the edge or point of an instrument, tool, or the like. Dull implies a lack or a loss of keenness or sharpness: a dull razor or saw. Blunt may mean the same or may refer to an edge or point not intended to be keen or sharp: a blunt or stub pen; a blunt foil. Dull, blunt, slow, stupid are applied to mental qualities. Dull implies obtuseness, lack of imagination: a dull child. Blunt implies loss of original keenness of intelligence through disease, sad experience, or the like: His critical faculties were blunt. Slow applies to a sluggish intellect: a slow mind. Stupid implies slowness of mental processes, but also lack of intelligence, wisdom, prudence, etc.: a stupid person.

Other Word Forms

• dullish adjective
• dullness noun
• dully adverb
• dulness noun
• undulled adjective

Etymology

Origin of dull

First recorded in 1200–50; Middle English; akin to Old English dol “foolish, stupid”; cognate with German toll

Explanation

To dull something means to take away its edge, its energy, or its excitement. "Watching that movie will dull your senses, until you fall asleep." Let’s think of something interesting about dull. Hmm. It can be a verb or an adjective! So when you’re reading a dull or boring word description, for instance, it can dull or deaden your appetite for reading more word descriptions. That’s pretty fascinating, no? You can even use it for physical things, like a knife, which you can dull, that is, make it less sharp. You can even dull something visual, making it lacking in light, or use it describe pain — you know, the kind that is not sharp, just an ache. Exciting? No — dull.

Example Sentences

Her initial dull, daunting task involves measuring and otherwise assessing the churches’ “apertures” — windows and doors.

From Los Angeles Times • Apr. 22, 2026

When I drove up, the gate was open, though there were no other cars; from its dull roar, I could tell the plant was not totally idle.

From Slate • Apr. 20, 2026

But they also lost some tremendous youth by giving up on Jackson, who averaged nearly 15 points last season and provided much-needed energy to another deadly dull squad.

From Los Angeles Times • Apr. 15, 2026

When individuals voluntarily dull their reasoning, they become more susceptible to poor decisions that hurt not only themselves but their families and communities.

From The Wall Street Journal • Apr. 14, 2026

Something dropped with a dull thud, prompting Jackson to get up and assist.

From "Boy 2.0" by Tracey Baptiste

Related Words

• cloudy
• cold
• dark
• dim
• dismal
• flat
• hazy
• lifeless
• muddy
• muted
• obscure
• soft
• somber
• subdued