Synonyms for Undertaking:

n.

bargain, common ground, accord, agreement, understanding, deal, consensus, unanimity, alliance. dedication, care, challenge, strain, heavy lifting, exertion, work. box, casket, cremate, burial, cortege, cremains, bier, coffin, Ashes, bury. action (noun)
enterprise.
endeavor (noun)
deed, effort, essay, action, engagement, venture, contract, performance, gambit, enterprise, aim, purpose, job, maneuver, project, assay, production, attempt, adventure, approach, endeavor, commitment, exploit.
endeavor, attempt (noun)
deal, essay, adventure, engagement, project, pursuit, affair, venture, move, trial, effort, hazard, experiment, job, striving, work, task, enterprise.
enterprise (noun)
hazard, trial, Emprise, move, experiment.
pursuit (noun)
lodestar, aspiration, vocation, profession, destination, target, quest, life work, search, mission, goal, ambition, objective, intention.
undertaking (noun)
project, task, labor.
venture (noun)
feat, initiative, activity, affair, task, pursuit, procedure, scheme, campaign.

v.

beginning (verb)
sprouting, starting, Inaugurating, beginning, Forming, initializing, springing, Conceiving, Introducing, Germinating, budding, Stemming, Originating, Commencing, Preparing, developing, Creating, emerging, birthing, dawning, Embarking, hatching, Inducting.
endeavoring (verb)
acting, Venturing, Aiming, Volunteering, contracting, proceeding, Attempting, Committing, Assaying, performing, engaging, approaching, exploiting, Endeavoring, Maneuvering.
pursuing (verb)
aspiring, following, hunting, tailing, trailing, Chasing, Intending, sleuthing, Harrying, stalking, searching, striving, questing, seeking, dogging, tracking.
venturing (verb)
pursuing, Doing, Initiating, scheming, campaigning.

Other synonyms:

exertion, heavy lifting. dedication, experiment, challenge. strain, work. care. Other relevant words:
challenge, casket, bargain, dedication, accord, trial, cremains, experiment, work, agreement, care, box, Emprise, move, consensus, strain, unanimity, exertion, understanding, cremate, bier, cortege, Ashes, labor, alliance, deal, burial, coffin, bury, hazard.

Usage examples for undertaking

  1. It's a good deal of an undertaking he declared. – Under the Skylights by Henry Blake Fuller
  2. Did I succeed in my new undertaking – Forty Years a Gambler on the Mississippi by George H. Devol
  3. They urged him to continue his undertaking as they said that if he also found the source he was seeking " England will have done it"- and she did. – Fifty-One Years of Victorian Life by Margaret Elizabeth Leigh Child-Villiers, Countess of Jersey