1. a determined and enterprising person
with his/her drive and ambition, he/she is a real go-getter
A 'go-getter' is someone who is considered to be a highly motivated and enthusiastic person, someone who 'goes' and 'gets' what they want, or someone who is known to achieve their goals. You could use this in either social or professional situations, but it might be heard more in the context of workplace conversations. You might see someone walking around a busy office floor, talking to people and carrying papers, and you might think, "He's a real go-getter". Don't be fooled, though. He might just want you to think he is!