supporter

noun

1. 1

   a support for the genitals worn by men engaging in strenuous exercise

2. 2

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

3. 3

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

   my invaluable assistant

   they hired additional help to finish the work

4. 4

   someone who supports or champions something

5. 5

   a person who backs a politician or a team etc.

   all their supporters came out for the game

   they are friends of the library