D defs.my
Entry 2 senses Webster, 1913

Light-headed

/(līt"hĕd`ĕd)/ · Light·-head·ed · IPA
01 a. Disordered in the head; dizzy; feeling faint; delirious.
  1. 1.
    Disordered in the head; dizzy; feeling faint; delirious.
  2. 2.
    Thoughtless; heedless; volatile; unsteady; fickle; loose; lacking seriousness; given to frivolity; as, light-headed teenagers.