He is a nephew to Montague and a cousin and friend to Romeo. His name means well-wisher, which reflects to some degree Benvolio's role in the play as a loyal friend and a peace-maker.
Benvolio - His name suggests "benevolence."
Montague’s nephew, Romeo’s cousin and thoughtful friend, he makes a genuine effort to defuse violent scenes in public places, though Mercutio accuses him of having a nasty temper in private. He spends most of the play trying to help Romeo get his mind off Rosaline, even after Romeo has fallen in love with Juliet.