Follow-up (noun)

1. An action or event that serves as a continuation or repetition of a previous one.
2. A subsequent action or event, typically one that is intended to check or maintain progress.

Origin:

20th century: from follow, on the pattern of follow-on.

Examples:

1. She scheduled a follow-up appointment.
2. The follow-up meeting is next week.
3. He did a follow-up study.
4. The follow-up call to the customer.
5. The follow-up email to confirm the meeting.