The word "am participant" has a few antonyms depending on the context. If we're talking about being involved in an event or activity, then "not participating" or "spectator" are antonyms. If used in the context of being part of a group or team, then "non-member" or "outsider" could be antonyms. Additionally, if we're discussing participation in a discussion or debate, then "silent" or "unresponsive" could be considered antonyms. Finally, if we're referring to being an active listener, "not paying attention" or "distracted" could also be considered antonyms. Therefore, the antonyms for "am participant" vary based on the situation in which it is used.