1. having or causing a whirling sensation; liable to falling;
"had a dizzy spell""a dizzy pinnacle""had a headache and felt giddy""a giddy precipice""feeling woozy from the blow on his head""a vertiginous climb up the face of the cliff"
2. lacking seriousness; given to frivolity;
"a dizzy blonde""light-headed teenagers""silly giggles"