Contestant (noun)

1. A person who takes part in a contest or competition.
2. A person who disputes or challenges something.

Origin:

From latin contestant-, contestans, present participle of contestari ('to call to witness, call upon to contest').

Examples:

1. There were several contestants in the singing competition.
2. The two contestants were evenly matched.
3. The company is looking for contestants to participate in the game show.
4. The lawsuit attracted many contestants.