Existing only in imagination or fancy; not based on fact or practical considerations. Fanciful ideas are whimsical, imaginative, but often unrealistic or impractical.
From 'fancy,' which comes from 'fantasy,' ultimately from Greek 'phantasia' meaning 'appearance' or 'imagination.' The word evolved from describing the mental faculty of imagination to describing ideas that exist only in that imaginative realm.
Break it down: 'fancy' + 'full' = full of fancy ideas. It's not necessarily bad - fairy tales are fanciful and wonderful - but fanciful ideas often can't survive in the real world. Think of elaborate daydreams that are beautiful but impossible.
Complete word intelligence in one call. Free tier — 50 lookups/day.