Adjective

1. ambitious (vs. unambitious), pushful, pushy, aspirant, aspiring(prenominal), wishful, compulsive, determined, driven, manque, would-be(prenominal), overambitious, enterprising

usage: having a strong desire for success or achievement

2. ambitious, challenging, difficult (vs. easy), hard

usage: requiring full use of your abilities or resources; "ambitious schedule"; "performed the most challenging task without a mistake"

See also: ambitious (Dictionary)