› someone who you know well and like: Sarah's my best friend (= the friend I like most). Gordon is a friend of mine. I'm going to New York to visit some friends.
an old friend › someone who you have known and liked for a long time
be friends (with sb) › to know and like someone: I have been friends with Jo for years.
make friends (with sb) › to begin to know and like someone: He's shy and finds it difficult to make friends.