empty-headed vs light-headed

empty-headed and light-headed both are adjectives.

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

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

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

empty-headed (adjective)	light-headed (adjective)
lacking seriousness; given to frivolity	lacking seriousness; given to frivolity
	weak and likely to lose consciousness