A word for a feature that an object should not have

Question

I am traveling in a foreign country and my girlfriend asked me to buy her some clothes. She is fine with about anything and want me to surprise her, but I still want to check if there are some items I should avoid.

I have deal breaker in mind but it does not fit my intent I guess.

Example of sentence I would use it:

Me: I am about to go to the shopping mall. Is there any clothes you need.

Her: Anything. Except top with epaulets. That would be a deal breaker. I would never wear clothes with epaulets!

What word can I use in this context?

Answer 1

For something simple like clothing, there really aren't any dedicated nouns for an unwanted feature. We might use any number of adjectives meaning "forbidden" in certain contexts, but none consistently. More often we'd leave the avoidance as understood in context or we would use a phrase that moves the avoidance into the verb part of the sentence rather than as a noun.

For example:

"... with epaulets, avoid those. I would never..."

Or perhaps as a statement of preference in the same place:

"... with epaulets, I hate those. I would never..."

That said, if you're really wanting a noun, then in addition to Tᴚoɯɐuo's suggestion of "show-stopper" and your own "deal breaker" you might try no-no.

no-no: something that people are not supposed to do because it is not proper, safe, fashionable, etc.

Here the word describes the action of either buying or wearing a shirt with epaulets.

However, none of these words are really right in the context of an unwanted feature on a relatively low cost, unimportant item like a shirt. If it were a car, or a house, or a prospective mate, or a business contract, or a behavior, then yes. You could get away with any of these occasionally in this context, but if you tried to use these words frequently for this purpose it would sound strange.

Answer 2

A possibility would be show-stopper, something that stops the "show", prevents something from proceeding or causes it to fail.

Since the word has developed two meanings (something terribly good and something terribly bad) you could use it to refer to features of the clothing which are objectionable because they're unappealing (e.g. epaulets) or because they're too flattering or revealing (e.g. a see-though blouse).