1. [late 18C; 1900s] drunk; thus dizzy ward, the alcoholic ward.
2. [1930s] (UK) intoxicated by a drug.
3. [mid-19C–1900s] (US) startling, astonishing, vivid.
4. [late 19C+] (also dizzey, dizzy-ass) eccentric, mad, stupid.
5. [1920s+] obsessed by; thus dizzy with a dame, obsessed with a woman.
[1970s] foolish, stupid.
[late 19C] (US) a complete fool.
[late 19C+] (mainly Aus.) the absolute limit.
[1920s] (US) a psychiatric institution.
[1900s] (Aus.) to act in an uninhibited manner.