Definition of "Supporter" :

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

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

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

noun: someone who supports or champions something

noun: a person who backs a politician or a team etc.

"All their supporters came out for the game."