fist-pump

/F IH1 S T P AH0 M P/
noun
  1. 1

    The thrusting of one's fist, most commonly forward or upward, as in celebration.

verb
  1. 1

    To thrust one's fist, most commonly forward or upward, as in celebration.

Source: https://en.wiktionary.org/wiki/fist%20pump, https://en.wiktionary.org/wiki/fist-pump