Are case and fancy synonyms or antonyms?

"Case" and "fancy" are not synonyms or antonyms. They are entirely different words with different meanings:

* Case: A specific instance of something, a situation, or a legal proceeding.

* Fancy: A liking or preference, or something that is elaborate or decorative.

Let's look at some examples:

Case:

* "The detective investigated the case of the missing painting."

* "She made a strong case for a pay raise."

Fancy:

* "I have a fancy for chocolate cake."

* "The ballroom was decorated in a fancy style."

Therefore, "case" and "fancy" are not related in terms of meaning.