trainer

/T R EY1 N ER0/
noun
  1. 1

    A person who trains another; a coach.

  2. 2

    A person responsible for treating injuries sustained by players during matches; a physiotherapist.

  3. 3

    A running shoe or sneaker.

  4. 4

    A patch for a video game that applies cheats.

  5. 5

    A piece of indoor equipment allowing a bicycle to be ridden while stationary.

Source: https://en.wiktionary.org/wiki/trainer