definition of
lightheaded

[1] #1 lightheaded s. [faint, light, swooning, light-headed] 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". wn

[2] #2 lightheaded s. [airheaded, dizzy, empty-headed, featherbrained, giddy, light-headed, silly] lacking seriousness; given to frivolity; "a dizzy blonde"; "light-headed teenagers"; "silly giggles". wn