featherbrained vs empty-headed

featherbrained and empty-headed both are adjectives.

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

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

featherbrained and empty-headed: lacking seriousness; given to frivolity

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

featherbrained (adjective)	empty-headed (adjective)
lacking seriousness; given to frivolity	lacking seriousness; given to frivolity