1. earnest and conscientious activity intended to do or accomplish something

e.g. made an effort to cover all the reading material
wished him luck in his endeavor
she gave it a good try

Synonym: attempteffortendeavortry

2. a purposeful or industrious undertaking (especially one that requires effort or boldness)

e.g. he had doubts about the whole enterprise

Synonym: enterpriseendeavor