oneupmanship

/W AH1 N AH1 P M AH0 N SH IH0 P/
noun
  1. 1

    The art or practice of successively outdoing a competitor.

    โ€œThey are bent on one-upmanship. I think it's hopeless to try to stop them.โ€

  2. 2

    A succession of instances of outdoing a competitor.

Source: https://en.wiktionary.org/wiki/one-upmanship, https://en.wiktionary.org/wiki/oneupmanship