outpouring vs effusion

outpouring and effusion both are nouns.

Word	Noun	Adjective	Verb	Adverb
outpouring	Yes	No	No	No
effusion	Yes	No	No	No

As nouns, effusion is a hyponym of outpouring; that is, effusion is a word with a more specific, narrower meaning than outpouring:

outpouring (noun)	effusion (noun)
a large flow	flow under pressure
the rapid and continuous delivery of linguistic communication (spoken or written)	an unrestrained expression of emotion
the pouring forth of a fluid
a sudden rapid flow (as of water)
a natural flow of ground water