noun (n)

• a person who backs a politician or a team etc.(noun.person)

  Synonym:
  admirer, champion, friend, protagonist, supporter
  

  source: wordnet30
• someone who is an active supporter and advocate(noun.person)

  Synonym:
  plugger, promoter
  

  source: wordnet30
• a thief who steals goods that are in a store(noun.person)

  Synonym:
  lifter, shoplifter
  

  source: wordnet30
• an amplifier for restoring the strength of a transmitted signal(noun.artifact)

  Synonym:
  booster amplifier, booster station, relay link, relay station, relay transmitter
  

  source: wordnet30
• the first stage of a multistage rocket(noun.artifact)

  Synonym:
  booster rocket, booster unit, takeoff booster, takeoff rocket
  

  source: wordnet30
• an additional dose that makes sure the first dose was effective(noun.artifact)

  Synonym:
  booster dose, booster shot, recall dose
  

  source: wordnet30
• An instrument for regulating the electro-motive force in an alternating- current circuit; -- so called because used to "boost", or raise, the pressure in the circuit.(noun)

  source: webster1913