thermal spring vs outpouring

thermal spring and outpouring both are nouns.

Word	Noun	Adjective	Verb	Adverb
thermal spring	Yes	No	No	No
outpouring	Yes	No	No	No

As nouns, outpouring is a hypernym of thermal spring; that is, outpouring is a word with a broader meaning than thermal spring:

Other hypernyms of thermal spring include fountain, natural spring, outflow, spring.

thermal spring (noun)	outpouring (noun)
a natural spring of water at a temperature of 70 F or above	a large flow
	the rapid and continuous delivery of linguistic communication (spoken or written)
	the pouring forth of a fluid
	a sudden rapid flow (as of water)
	a natural flow of ground water