ambitious

modif.

1. Characterized by ambition

   aspiring, enterprising, emulous, hopeful, zealous, high-reaching, climbing, eager, aggressive, earnest, determined, industrious, driven, goal-oriented, hungry, thirsty, itching, designing, scheming, pushing, emulous of fame, anxious for power, resourceful, opportunistic, energetic, enthusiastic, driving, striving, avid, sharp, intent, vaulting, up and coming, upwardly mobile, careerist, power-hungry, overambitious, predatory, hustling*, pushy*, high-flying*, on the fast track*, on the make*.

   Antonyms unambitious, lackadaisical, indolent.

2. Challenging

   arduous, formidable, lofty, pretentious; see difficult 1, grand 2.

ambitious implies a striving for advancement, wealth, fame, etc., and is used with both favorable and unfavorable connotations; aspiring suggests a striving to reach some lofty end regarded as somewhat beyond one's normal expectations an aspiring young poet; enterprising implies an energetic readiness to take risks or undertake new projects in order to succeed; emulous suggests ambition characterized by a competitive desire to equal or surpass another