GAGA

crazy, wild, dotty, gaga

(adjective) intensely enthusiastic about or preoccupied with; “crazy about cars and racing”; “they are dotty about each other”; “gaga over the rock group’s new album”

doddering, doddery, gaga, senile

(adjective) mentally or physically infirm with age; “his mother was doddering and frail”

Source: WordNet® 3.1

Etymology 1

Adjective

gaga (comparative more gaga, superlative most gaga)

(informal) Mentally senile.

(informal) Crazy.

(informal) Infatuated.

Usage notes

• As demonstrated in the example sentences above, gaga is often preceded by the verb go.

Etymology 2

Noun

gaga (uncountable)

Alternative form of ga-ga (“game resembling dodgeball”)

Source: Wiktionary