lightheaded vs giddy

lightheaded and giddy both are adjectives.

Word	Noun	Adjective	Verb	Adverb
lightheaded	No	Yes	No	No
giddy	No	Yes	No	No

As adjectives, lightheaded and giddy are synonyms defined as:

Other synonyms of lightheaded include airheaded, dizzy, empty-headed, featherbrained, light-headed, silly.

lightheaded (adjective)	giddy (adjective)
lacking seriousness; given to frivolity	lacking seriousness; given to frivolity
weak and likely to lose consciousness	having or causing a whirling sensation; liable to falling