Contestant
Part of speech: noun
Definition: A participant in a contest
Example sentence: Part of my job as a food writer is to describe food. So my work on 'Top Chef,' I feel, is an extension of that. When we give a criticism to the contestant, we want to make sure we tell them why it's not working and why it would work if they did it a different way.
Dissenter
Part of speech: noun
Definition: someone who dissents (disagrees), especially from an established church