What is what does it mean when snapchat says accept friend?

When Snapchat says "accept friend," it means that someone has added you as a friend on the app, and you have received a notification asking you to accept their friend request. Accepting the friend request will allow you and the other user to send snaps and messages to each other on the app. You can choose to accept or ignore the friend request, depending on whether you want to add the user as a friend or not. If you accept the friend request, the other user will be added to your Snapchat friend list, and you will be added to theirs.