What's a word that can mean both "good" and "bad"? [closed]

Solution 1:

The colloquial expression sick covers both of those bases.

Solution 2:

I don't know what term you may be referring to, but bear in mind that irony can always turn anything to mean its opposite.

You passed your mid term exams? Good ! What's next? The finals?
You killed your cat? Good ! What's next? Your parents?

Solution 3:

Maybe you've heard "awesome"? It literally means something that creates fear, but it's used in colloquial situations to express that something is "great", "fantastic" or "cool".

Solution 4:

The question is an interesting one. If it is about feelings for a thing or person, a formal option could be "ambivalent", if it is supposed to evoke both good and bad reactions / love and hate emotions about a thing or a person.

Another interesting case could be a word, that can be interpreted to be either good or bad, and the person who used the term meant only one of those, not both. Such a word is "fantastic" and also a reason @Raku should not have used it in his answer. If I say, "John gave us fantastic support at the time of crisis", I may have meant it in a good way, that his support was really something beyond what could be expected, or in a bad way, I may have meant that his support was not of any worth, it was unreal, imaginary, fantastic. There are similar other words, which you can think of.