retrospect vs reflexion

retrospect and reflexion both are nouns.

Word	Noun	Adjective	Verb	Adverb
retrospect	Yes	No	Yes	No
reflexion	Yes	No	No	No

As nouns, reflexion is a hypernym of retrospect; that is, reflexion is a word with a broader meaning than retrospect:

Other hypernyms of retrospect include contemplation, musing, reflection, rumination, thoughtfulness.

retrospect (noun)	reflexion (noun)
contemplation of things past	the image of something as reflected by a mirror (or other reflective material)
	the ability to reflect beams or rays
	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

retrospect (verb)	reflexion (verb)
look back upon (a period of time, sequence of events); remember