lightheaded

US: /ˈlaɪtˈhɛdɪd/ ,(līt′hed′id)

WordReference Random House Learner's Dictionary of American English © 2025

light•head•ed /ˈlaɪtˈhɛdɪd/   adj. 

1. giddy;
   dizzy.
2. frivolous;
   foolish.

WordReference Random House Unabridged Dictionary of American English © 2025

light•head•ed  (līt′hed′id), adj. 

1. giddy, dizzy, or delirious:
   After two drinks Pat began to feel lightheaded.
2. having or showing a frivolous or volatile disposition;
   thoughtless:
   lightheaded persons.

• light² + head + -ed³ 1530–40

light′head′ed•ly, adv. 
light′head′ed•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

light-headed adjective

1. frivolous in disposition or behaviour
2. giddy; feeling faint or slightly delirious

ˌlight-ˈheadedly adverb

ˌlight-ˈheadedness noun