giddy vs empty-headed

giddy and empty-headed both are adjectives.

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

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

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

giddy (adjective)	empty-headed (adjective)
lacking seriousness; given to frivolity	lacking seriousness; given to frivolity
having or causing a whirling sensation; liable to falling