To watch an event as a viewer, like a game or a performance.
Spectating can be fun and exciting, like being part of something even if you're not really doing it.
Examples:
We can spectate the game from the stands.
She likes to spectate the dance competition.
They spectate the show from their seats.
I spectate the race and cheer for my friend.
We spectate the rocket launch from far away.
He spectates the play and claps at the end.