noun
ambitious person; go-getter
Refers to a person with strong ambition, often with a nuance of being driven or power-hungry. Can be neutral or slightly negative depending on context.
彼は若い頃から野心家で、いつか社長になりたいと思っていた。
He has been an ambitious person since he was young, always wanting to become a company president someday.
あの政治家は野心家として知られている。
That politician is known as an ambitious person.