light-headed in WordNet English dictionary

1. lacking seriousness; given to frivolity
   "a dizzy blonde"; "light-headed teenagers"; "silly giggles"
   airheaded  dizzy  empty-headed  featherbrained  giddy  light-headed  lightheaded  silly 
   
2. weak and likely to lose consciousness
   "suddenly felt faint from the pain"; "was sick and faint from hunger"; "felt light in the head"; "a swooning fit"; "light-headed with wine"; "light-headed from lack of sleep"
   faint  light  swooning  light-headed  lightheaded