The Oxford Thesaurus An A-Z Dictionary of Synonyms - undertakingn.

1) enterprise, affair, business, project, task, effort, venture, work, feat: The scope of the undertaking was far beyond her capacity. 2) doing, performing, performance, realization, achievement: Giles's undertaking of the work makes me feel more confident. 3) promise, pledge, commitment, assurance, contract, agreement, vow, guarantee or guaranty, warranty: You gave an undertaking to complete the work by Friday.