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1. To join a group or organization of some kind. The army recruiters work to get young people to join up. Now that the organization is more inclusive, we're seeing a lot more people joining up.
2. To work together or collaborate; team up. The two charities are joining up to raise awareness about the cause. If we all join up, we can get done in half the time.
3. To connect. Once we join up those pipes, the connection will be complete.
to join some organization. The club has opened its membership rolls again. Are you going to join up? I can't afford to join up.
1. To become a member of some group or organization: After the recruiter's speech, I decided to join up.
2. To collaborate or team up with someone: The advertising firm joined up with the baseball team to promote the new manager.
3. To connect together: The points join up to form a straight line.
4. To connect something with some other thing: Join up the dots, and you'll see a picture. When we join these pieces up, the puzzle will be completed.