Someone involved in a contest or battle (as in an agon), protagonist.
The muscle that contracts while the other relaxes.
A molecule that can combine with a receptor on a cell to produce a physiological reaction.
A person who supports, promotes, advocates or champions a cause, movement, or political party; an adherent.
A person who provides moral or physical support to another; an attendant participating in a ceremony or procession.
Someone who is a fan of a certain sports team or sportsperson.
A garter worn around the leg to support a sock or stocking.
Something that supports a structure such as a building or a sculpture.
An animal or figure that supports a shield in a coat of arms.
Something that supports another thing.