fancy (n.)

mid-15c., fantsy "inclination, liking," contraction of fantasy. It took the older and longer word's sense of "inclination, whim, desire." Meaning "the productive imagination" is from 1580s. That of "a fanciful image or conception" is from 1660s. Meaning "fans of an amusement or sport, collectively" is attested by 1735, especially (though not originally) of the prize ring. The adjective is recorded from 1751 in the sense "fine, elegant, ornamental" (opposed to plain); later as "involving fancy, of a fanciful nature" (1800). Fancy man attested by 1811.

fancy (v.)

"take a liking to," 1540s, a contraction of fantasien "to fantasize (about)," from fantasy (n.). Meaning "imagine" is from 1550s. Related: Fancied; fancies; fancying. Colloquial use in fancy that, etc. is recorded by 1813.