backsie

/B AE1 K S IY0/
noun
  1. 1

    (childish) The back.

  2. 2

    (childish, often in the plural) The act of taking back or going back on a statement, promise, or agreement.

  3. 3

    (childish, often in the plural) A reciprocal action or consequence, such as immediately tagging the player who has tagged one in a game of tag.

  4. 4

    (childish, often in the plural) The act of joining a queue behind a friend rather than at the end of the queue.

  5. 5

    (jacks, often in the plural) The act of going through a sequence of moves in reverse.