Street name for 2mg tablets of Xanax (Alprazolam). The name is derived from the three scores down one side of the long, white tablet, making them divisible by four. The scoring resembles the children's playground equipment 'monkey bars'.
Just like monkeybars, you hold onto one bar before grabbing the next. The Monkeybar Effect is the same only with a woman who will keep her man only until she finds another man of equal or superior quality.