swollen-headed vs vain

swollen-headed and vain both are adjectives.

Word	Noun	Adjective	Verb	Adverb
swollen-headed	No	Yes	No	No
vain	No	Yes	No	No

As adjectives, swollen-headed and vain are synonyms defined as:

swollen-headed and vain: characteristic of false pride; having an exaggerated sense of self-importance

Other synonyms of swollen-headed include conceited, egotistic, egotistical, self-conceited, swollen.

swollen-headed (adjective)	vain (adjective)
characteristic of false pride; having an exaggerated sense of self-importance	characteristic of false pride; having an exaggerated sense of self-importance
	unproductive of success