1. (Football) A kick from the center of the field to start a football game or to resume it after a score.

2. The time at which something is supposed to begin.

3. (In business) It means something such as a project, an event or activity commences officially, .

4. A kick-off meeting means to have a meeting and announce to start a project or something formally.

5. Sales kick-off means to start selling something formally.

6. A kick-off ceremony means to have a ceremony and announce to start something formally.