From the [Grammarist][1]:

> Kick-off is also an adjective that describes a noun that comes first. It can be something in a sports event, meeting, seminar, etc. Check out these examples:
>
> - *I’m throwing a kickoff party for his first game.* 


  [1]: https://grammarist.com/spelling/kick-off-kickoff/#:~:text=Kick%2Doff%20is%20also%20an,party%20for%20his%20first%20game.