What are some adjectives that have no opposites?

Horny

red, yellow, blue etc. They have complimentary colors, but not opposites; except black and white.

thirsty

horny—- frigid

I can’t think of any except strict antonyms where removing the prefix doesn’t leave you with a usable opposite word. Ex. intact where tact doesn’t mean broken into pieces.

Disgruntled of course.

Nonplused might have an opposite, but it’s not plused

Thirsty – Sated?

overwhelmed

Chartreuse. Red.

@jaytkay

Nonplussed—- Excited?

@Zaku

Chartreuse. The only liquor so good they named a color after it.

Some nouns can serve as adjectives, and they usually don’t have direct or unhyphenated opposites.

E.g., paper and snow. Perhaps one could say non-paper or anti-snow, but those are more categorical exclusions than they are opposites.

@Blueroses Underwhelmed.

soporific?

vampiresque

I think that any adjective has an opposite by adding a not to the beginning or just changing part of the word (like the prefix or suffix). So to the best of my mere knowledge, I don’t think there is one.
What about numbers? I suppose those have no direct/definite opposites.

Well, @dxs, by your language logic, which is fine (thirsty——not thirsty), I would postulate that any number’s opposite is simply adding a + or – in front of it.

@Blueroses there we go… knew there was a catch to the numer thing
What about the opposite of zero? beat that!

@dxs Zero is its own opposite. It’s a very powerful (not)number XD

Flippity-flappity

Examples of this word used in sentences:

When that hound dog was riding in the car, sticking his head out of the window, his ears went all flippity-flappity.

When Pamela Anderson went running down the beach in her skimpy little bikini, her boobies went all flippity-flappity.

@Sunny2 I think that that counts as an opposite.
@Blueroses I was figuring that, but I don’t know if that is completely true. it’s really late and I am too tired to do much, sorry :(

I think that everything has to have an opposite because without an opposite, there is nothing to compare to; it couldn’t be defined. Without evil there is no good; without Satan there is no God.

@janbb: soporific (n.) – stimulant?

Nine as in nine days. Or do numbers that modify have a different name than adjective?
@dsx I still think colors qualify. Black and white are opposites, but colors don’t have opposites. I think you can put an ‘un’ or non’ in front of a lot of adjectives and it is a challenge to find adjectives that do not have opposites.

Gray

Uncouth? though we have the word ‘couthie’ in Scotland.

numbers – two pencils, pi radians
angry, annoying, schizophrenic, compulsive, murderous
gaseous
floating, suspended