fancy has 15 distinct synonyms spread across 4 of its 6 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is plain.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
something many people believe that is false
“they have the illusion that I am very wealthy”
imagination or fantasy; held by Coleridge to be more casual and superficial than true imagination
“never had the wildest flights of fancy imagined such magnificence”
a predisposition to like something
“he had a fondness for whiskey”
not plain; decorative or ornamented
“fancy handwriting”
Synonyms, antonyms and the broader and narrower relations for fancy come from Princeton University’s WordNet. Full sources and licences.