A mentor is someone who helps a more junior person learn, develop and achieve her professional goals. (slaw.ca)
Currently, much legal work (e.g., drafting and reviewing contracts) gets done by junior people who may be smart but still have a lot to learn. (law21.ca)
When a team reaches a certain level of output, it splits — and junior people on the old team can move into more senior positions on the new. (inc.com)