Pronunciation: (am-bish'us),[key] —adj. 1. having ambition; eagerly desirous of achieving or obtaining success, power, wealth, a specific goal, etc.: ambitious students. 2. showing or caused by ambition: an ambitious attempt to break the record. 3. strongly desirous; eager: ambitious of love and approval. 4. requiring exceptional effort, ability, etc.: an ambitious program for eliminating all slums.