Synonyms for Rethink:

n.

contemplate, reconsider, consider, reevaluate, evaluate, think over, assess, thoughts, review, take something into consideration, reexamine, take a long hard look at someone/something, think out, ponder, plan. concentration, forethought, reasoning, soul-searching, introspection, focus, reflection, thought, assessment, consideration. rethink (noun)
afterthought, second thought, reconsideration.
review (noun)
reconsideration, second thought, reflection.

v.

rethink (verb)
reexamine, review, think over, reevaluate.
review (verb)
reconsider.

Other synonyms:

reevaluate. reexamine. review. reevaluate
reconsider.
Other relevant words:
concentration, review, reconsider, consideration, contemplate, forethought, assessment, evaluate, consider, soul-searching, plan, reevaluate, think over, thought, reexamine, ponder, assess, reflection, introspection, thoughts, focus, reasoning.