kickoff

1. Football. A place kick in football that starts play at the beginning of a half or after a team has scored.
2. Sports.
   1. A kick of a stationary ball from the middle of the field in soccer that starts play at the beginning of a half or after a goal has been scored.
   2. A similar kick in Rugby.
3. Informal. A beginning: the kickoff of a charity campaign.

noun

The act or process of bringing or being brought into existence: beginning, commencement, inauguration, inception, incipience, incipiency, initiation, launch, leadoff, opening, origination, start. See start/end.

The noun has 3 meanings:

Meaning #1: a kick from the center of the field to start a football game or to resume it after a score

Meaning #2: the time at which something begins
  Synonyms: beginning, commencement, first, outset, start, starting time, offset

Meaning #3: a start given to contestants
  Synonyms: send-off, start-off