taru-adjective, adverb taking the 'to' particle
ambitious; aspiring
A yojijukugo describing a person's spirit or attitude as full of ambition and drive. Often used in literary or formal contexts.
彼は雄心勃勃として新事業に取り組んだ。
He tackled the new venture with great ambition.
その若者は雄心勃勃たる志を抱いていた。
The young man harbored ambitious aspirations.
意欲的 is a more common, everyday adjective for 'ambitious' or 'motivated', while 雄心勃勃 is a literary yojijukugo with a stronger, more dramatic nuance.
A yojijukugo composed of 雄心 (ambitious spirit) and 勃勃 (rising vigorously). The exact historical origin is uncertain, but it follows a common pattern of four-character compounds expressing strong personal qualities.