ETYM From Craze.
1. Insane; mentally deranged; SYN. insane, deranged, demented, psychologically disturbed.
2. Marked by foolish or unreasoning fondness; SYN. dotty, gaga, enamored, infatuated, in love, smitten, soft on, taken with.
3. Bizarre or fantastic.
4. (Informal) Possessed by inordinate excitement.
5. (Informal) Intensely enthusiastic about or preoccupied with.
6. (Informal) Foolish; totally unsound; SYN. half-baked, screwball, softheaded.