flatten out

/F L AE1 T AH0 N AW1 T/
verb
  1. 1

    To make flat (something rough, folded or bumpy).

  2. 2

    (of a hierarchy or inequal distribution) To become more even.

  3. 3

    To win a fight, usually by punching someone until they are knocked over

Source: https://en.wiktionary.org/wiki/flatten%20out