The term 'One on the Other Side' can be described by four different crossword solutions: ENEMY (5 letters), FOE (3 letters), RIVAL (5 letters), and foeman (6 letters). An ENEMY is someone who is actively hostile or opposed to another, while a FOE is an ENEMY or opponent. A RIVAL is someone who competes with another for the same objective or goal, and a foeman is an ENEMY or adversary. All of these terms refer to someone who is on the opposite side of another person or group.