supporter

Noun

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

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

• 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
    

• someone who supports or champions something

• a person who backs a politician or a team etc.
  • all their supporters came out for the game
    
  • they are friends of the library
    

Related words

• Synonyms: 
  athletic supporter , suspensor , jockstrap , jock , garter , assistant , helper , help , patron , sponsor , protagonist , champion , admirer , booster , friend