Definitions of join:

• noun:   the shape or manner in which things come together and a connection is made
• noun:   a set containing all and only the members of two or more given sets
• verb:   become part of; become a member of a group or organization

  Example: "He joined the Communist Party as a young man"

• verb:   come into the company of

  Example: "She joined him for a drink"

• verb:   make contact or come together

  Example: "The two roads join here"

• verb:   cause to become joined or linked

  Example: "Join these two parts so that they fit together"

• verb:   be or become joined or united or linked

  Example: "Our paths joined"