A participant is someone who takes part in an activity, event, or experience. When you join a science fair, you're a participant in the fair. When your class holds a debate, each student who speaks is a participant in the discussion.

The word comes from a Latin root meaning “to take part,” and that's exactly what participants do: they don't just watch from the sidelines, they get involved. In a spelling bee, the participants are the students spelling words on stage, not the audience members watching. In a research study, participants are the people who volunteer to be tested or observed.

You'll often see the word in formal contexts. A teacher might say, “All participants in the field trip must return permission slips.” A sports announcer might say, “The marathon had over 5,000 participants this year.” It's a flexible word that works for any situation where people are actively involved, whether it's a piano recital, a town cleanup day, or a birthday party scavenger hunt.

The opposite of a participant is a spectator or observer: someone who watches but doesn't join in. Being a participant means you're part of the action.