nasty

¹ American  

[nas-tee] / ˈnæs ti /

adjective

nastier, nastiest

1. physically filthy; disgustingly unclean.

   a nasty pigsty of a room.

   Synonyms:

   grimy, foul, dirty

   Antonyms:

   unstained, spotless, immaculate, clean

2. offensive to taste or smell; nauseating.

   This ointment is really nasty—couldn't they make it smell less vile?

   Synonyms:

   ugly, catty, bitchy, malevolent, malicious, mean, repellent, repulsive, sickening

3. offensive; objectionable.

   a nasty habit.

4. vicious, spiteful, or unkind.

   a nasty dog;

   a nasty rumor.

5. bad or hard to deal with, encounter, undergo, etc.; dangerous; serious: a nasty accident.

   a nasty cut;

   a nasty accident.

6. very unpleasant or disagreeable.

   nasty weather.

   Synonyms:

   inclement, stormy

7. morally filthy; obscene; indecent.

   a nasty word.

   Synonyms:

   smutty

8. Slang. formidable: a young pitcher with a nasty slider.

   the raw, nasty power of this engine;

   a young pitcher with a nasty slider.

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noun

plural

nasties

1. Informal. a nasty person or thing.

-nasty ² American  

1. a combining form with the meaning “nastic pressure,” of the kind or in the direction specified by the initial element.

   hyponasty.

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nasty ¹ British  

/ ˈnɑːstɪ /

adjective

1. unpleasant, offensive, or repugnant

2. (of an experience, condition, etc) unpleasant, dangerous, or painful

   a nasty wound

3. spiteful, abusive, or ill-natured

4. obscene or indecent

5. informal a cruel or mean person

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noun

1. an offensive or unpleasant person or thing

   a video nasty

-nasty ² British  

combining form

1. indicating a nastic movement to a certain stimulus

   nyctinasty

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Other Word Forms

• -nastic combining form
• nastily adverb
• nastiness noun

Etymology

Origin of nasty¹

First recorded in 1350–1400; Middle English, further origin unknown

Origin of -nasty²

< Greek nast ( ós ) pressed close ( see nastic) + -y ³

Explanation

Something nasty is filthy, foul, dirty, or awful. Nasty isn't a word for anything nice. The main meaning of nasty is for things that are unpleasant and very gross. If someone throws up in class, at least one student will probably say, "That's nasty!" The smell of a bathroom is nasty. A song full of dirty words is nasty in a different way. Nasty can also mean "extremely." In football, a vicious hit can be called a nasty hit. A mean person is a nasty person too.

Example Sentences

And they developed a nasty habit of blowing big leads—since 2011-12, they’ve lost 60 games after holding a two-goal advantage.

From The Wall Street Journal • Apr. 15, 2026

Doncaster's Harper, who suffered a nasty cut after a clash of heads in the eighth, showed great spirit to continue throwing until the final round.

From BBC • Apr. 5, 2026

Laing laughs as he recalls one nasty comment that stuck.

From BBC • Apr. 4, 2026

She’s a 16-year-old Labrador retriever who became the target of a nasty custody fight between a California couple after the dissolution of their domestic partnership.

From Los Angeles Times • Mar. 27, 2026

“I’d give you a nasty look for that one,” said George, “but I see you’ve already got one.”

From "Two Degrees" by Alan Gratz

Related Words

• awful
• dirty
• fierce
• horrible
• icky
• murderous
• noxious
• obnoxious
• ornery
• outrageous
• rough
• tough
• unpleasant
• vile
• vulgar