empty-headed vs giddy

empty-headed and giddy both are adjectives.

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

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

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

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