giddy vs light-headed

giddy and light-headed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
giddy	No	Yes	No	No
light-headed	No	Yes	No	No

As adjectives, giddy and light-headed are synonyms defined as:

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

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