To take the place of someone or something, so that the old one is no longer used or no longer has power. The key is replacement: the new thing pushes the old thing out. "Email has largely supplanted the letter." "He was supplanted as leader by a younger man." It is a formal word — you meet it in news writing, history books and business reports, not in ordinary chat. Speakers say replace or take over instead. There is often a small feeling of struggle or unfairness in it, because of where the word came from. When it is about people, supplant frequently suggests that the new person schemed or pushed to get the position: "She supplanted her rival at the top of the company." When it is about things — technologies, methods, materials — that feeling is weaker; it just means one thing won and the other faded away. Notice also that supplant is usually about something well established being displaced, not about a small swap. You would not say you supplanted your old phone with a new one.

取代、把…擠掉。比 replace 正式，而且帶有「把原本的人事物排擠掉、頂替掉」的味道；用在人身上時常暗示是靠手段爬上去的。