Green’s Dictionary of Slang

dizzy adj.

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.

In compounds

dizzy-ass (adj.) [-ass sfx]

[1970s] foolish, stupid.

dizzy flat (n.) [flat n.2 (1) + the image of stupidity so great that it makes witnesses giddy]

[late 19C] (US) a complete fool.

dizzy limit (n.) (also lurid limit)

[late 19C+] (mainly Aus.) the absolute limit.

In phrases

dizzy sanitarium (n.)

[1920s] (US) a psychiatric institution.

do the dizzy (v.)

[1900s] (Aus.) to act in an uninhibited manner.