It means to act foolishly. There are many forms of this phrase too such as in the British comic Ally Sloper's Half-Holiday used the phrase in a March 1892 edition:
"Fanny Robinson was flighty; she played the giddy ox - I mean, heifer."
Also the phrase "Acting the goat" can mean the same thing like in the memoir Stray Leaves from a Military Man's Note Book:
"Don't be actin' the goat."
Giddy mau can mean three things, it usually means go away, but it can also mean do it now,or it can mean that's enough
giddy
giddy giddy
The Christmas song that includes the lyrics "giddy-up giddy-up giddy up grand" is "Jingle Bell Rock."
While walking home, I felt giddy.
It's what you say to a horse when you want it to start moving.
I feel giddy
sleigh ride
Stallion Horses are quite Giddy....
Giddy Up was created in 2001.
Laura Bell Bundy
A polled goat is hornless.