Ambitious and Emulous both mean extremely desirous of something that will give one power, fame, success, or riches.
Ambitious often implies inordinate, sometimes presumptuous, eagerness to advance oneself or to attain something beyond one’s present reach; it may, in addition, connote aggressiveness in the pursuit of one’s ends.
- the noble Brutus hath told you Caesar was ambitious: if it were so, it was a grievous fault
—Shak.
Emulous stresses the desire to equal or surpass others; it can suggest covetous rivalry or merely the spirit of competition.
- men of pedigree . . . emulous always of the nearest place to any throne, except the throne of grace
—Cowper