flip-flop vs rethink

flip-flop and rethink both are nouns.

Word	Noun	Adjective	Verb	Adverb
flip-flop	Yes	No	Yes	No
rethink	Yes	No	Yes	No

As nouns, rethink is a hyponym of flip-flop; that is, rethink is a word with a more specific, narrower meaning than flip-flop:

Other hyponyms of flip-flop include afterthought, reconsideration, second thought.

flip-flop (noun)	rethink (noun)
a backward somersault	thinking again about a choice previously made
an electronic circuit that can assume either of two stable states
a backless sandal held to the foot by a thong between the big toe and the second toe
a decision to reverse an earlier decision

flip-flop (verb)	rethink (verb)
reverse (a direction, attitude, or course of action)	change one's mind