adj. 25B6; adjective
she felt giddy : DIZZY, light-headed, faint, weak, vertiginous; unsteady, shaky, wobbly, reeling; informal woozy.
she was young and giddy : FLIGHTY, silly, frivolous, skittish, irresponsible, flippant, whimsical, capricious; feather-brained, scatty, thoughtless, heedless, carefree; informal dippy; N. Amer. informal ditzy.
steady, sensible.