Related Clues:

• Mass
• Go from two or more to one
• Join in wedlock
• Form an alliance
• Change from two to one
• Draw together
• Join in marriage
• Bond together
• Call to the workers of the world, perhaps
• Cease to be separate
• Say "I do"
• Make one of two?
• Come together, as in matrimony
• Form a group
• Form a merger