Definition from Wiktionary, the free dictionary
Alternative forms 
From Middle English, a contraction of fantasy, from Old French fantasie, from Medieval Latin fantasia, from Late Latin phantasia (“an idea, notion, fancy, phantasm”), from Ancient Greek (phantazein, “to render visible”)
fancy (plural fancies)
- The imagination; an imagined image.
- The film rose from Stephen's fancy.
- A whim.
- I had a fancy to learn to play the flute.
- Love or amorous attachment.
- He took a fancy to her.
- Any sport or hobby pursued by a group.
- Trainspotting is the fancy of a special lot.
- the cat fancy
- The enthusiasts of such a pursuit.
- He fell out of favor with the boxing fancy after the incident.
- A diamond with a distinctive colour.
Derived terms 
The imagination; an imagined image
Any sport or hobby pursued by a group
- This is a fancy shawl.
- Of a superior grade.
- This box contains bottles of the fancy grade of jelly.
- Executed with skill.
- He initiated the game winning play with a fancy, deked saucer pass to the winger.
- (colloquial) Unnecessarily complicated.
- I'm not keen on him and his fancy ideas.
- (formal) To appreciate without jealousy or greed.
- I fancy your new car, but I like my old one just fine.
- (UK) would like
- (UK, informal) To be sexually attracted to.
- I fancy that girl over there.
- (dated) To imagine, suppose.
- I fancy you'll want something to drink after your long journey
- Fancy meeting you here!
- Fancy that! I saw Elizabeth Bennett and Mr. Darcy kissing in the garden.
- 1895, H. G. Wells, The Time Machine Chapter X
- Now, I still think that for this box of matches to have escaped the wear of time for immemorial years was a strange, and for me, a most fortunate thing. Yet oddly enough I found here a far more unlikely substance, and that was camphor. I found it in a sealed jar, that, by chance, I supposed had been really hermetically sealed. I fancied at first the stuff was paraffin wax, and smashed the jar accordingly. But the odor of camphor was unmistakable. It struck me as singularly odd, that among the universal decay, this volatile substance had chanced to survive, perhaps through many thousand years. Is reminded me of a sepia painting I had once seen done from the ink of a fossil Belemnite that must have perished and become fossilized millions of years ago. I was about to throw this camphor on one side, and then remembering that it was inflammable and burnt with a good bright flame, I put it into my pocket.
Derived terms 
To be sexually attracted to
would like to