Origin: 1350–1400; ME < L
ambitiōsus, equiv. to
ambiti(
ō)
ambition +
-ōsus -ous 
Related forms: am⋅bi⋅tious⋅ly, adverb
am⋅bi⋅tious⋅ness, noun
Synonyms:
1. Ambitious, aspiring, enterprising describe a person who wishes to rise above his or her present position or condition. The ambitious person wishes to attain worldly success, and puts forth effort toward this end: ambitious for social position. The enterprising person, interested especially in wealth, is characterized by energy and daring in undertaking projects. The aspiring person wishes to rise (mentally or spiritually) to a higher level or plane, or to attain some end above ordinary expectations.
Antonyms:
1. apathetic, lackadaisical.