fountainhead vs headspring

fountainhead and headspring both are nouns.

Word	Noun	Adjective	Verb	Adverb
fountainhead	Yes	No	No	No
headspring	Yes	No	No	No

As nouns, fountainhead and headspring are synonyms defined as:

fountainhead and headspring: the source of water from which a stream arises

Other synonyms of fountainhead include head.

fountainhead (noun)	headspring (noun)
an abundant source	the source of water from which a stream arises
the source of water from which a stream arises