GYAT

GYAT :

'Goddam ya ass thick'
'Gawd you are thick'

GYATT:

'Goddam ya ass thick thick'
'Gawd ya ass thick thick'

When someone is looking at someone's backside and says 'GYAT', usually saying it in an impressed manner as they're delighted to see a big booty. Sometimes one will add emphasis and mean it as 'GYATT' dragging it out, meaning that booty is thick thick. Thick thick means as if they aren't joking or playing around. Usually very astonished by the site of a beautiful booty