giddy

adj. (-ier, -iest) 1 dizzy, tending to fall or stagger. 2 a mentally intoxicated (giddy with success). B excitable, frivolous, flighty. 3 making dizzy (giddy heights).  giddily adv. Giddiness n. [old english]

superl. Having in the head a sensation of whirling or reeling about; having lost the power of preserving the balance of the body, and therefore wavering and inclined to fall; lightheaded; dizzy.