supporter

A person who contributes to the fulfillment of a need or furtherance of an effort or purpose.

A support for the genitals worn by men engaging in strenuous exercise.

A person who backs a politician or a team etc.

“all their supporters came out for the game”

Someone who supports or champions something.

A band (usually elastic) worn around the leg to hold up a stocking (or around the arm to hold up a sleeve).