Definitions of repeater:

• noun:   (electronics) electronic device that amplifies a signal before transmitting it again

  Example: "Repeaters can be used in computer networks to extend cabling distances"

• noun:   a person who repeats

  Example: "The audience consisted largely of repeaters who had seen the movie many times"

• noun:   a firearm that can fire several rounds without reloading
• noun:   someone who is repeatedly arrested for criminal behavior (especially for the same criminal behavior)