rethink vs reconsideration

rethink and reconsideration both are nouns.

Word	Noun	Adjective	Verb	Adverb
rethink	Yes	No	Yes	No
reconsideration	Yes	No	No	No

As nouns, rethink and reconsideration are synonyms defined as:

rethink and reconsideration: thinking again about a choice previously made

Other synonyms of rethink include afterthought, second thought.

rethink (noun)	reconsideration (noun)
thinking again about a choice previously made	thinking again about a choice previously made
	a consideration of a topic (as in a meeting) with a view to changing an earlier decision

rethink (verb)	reconsideration (verb)
change one's mind