reflection vs effusion

reflection and effusion both are nouns.

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

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

Other hyponyms of reflection include lamentation, mourning, act, blowup, ebullition, gush, outburst.

reflection (noun)	effusion (noun)
the image of something as reflected by a mirror (or other reflective material)	flow under pressure
the ability to reflect beams or rays	an unrestrained expression of emotion
a likeness in which left and right are reversed
a calm, lengthy, intent consideration
a remark expressing careful consideration
expression without words
the phenomenon of a propagating wave (light or sound) being thrown back from a surface
(mathematics) a transformation in which the direction of one axis is reversed