balls-out

/B AO1 L Z AW0 T/
adjective
  1. 1

    Extreme, extremely great

adverb
  1. 1

    Descriptive of the use of a centrifugal governor at maximum speed.

  2. 2

    With great abandon.

  3. 3

    At the fastest possible speed.

Source: https://en.wiktionary.org/wiki/balls-out