light-headed vs featherbrained

light-headed and featherbrained both are adjectives.

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

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

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

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

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