testing ground

/T EH1 S T IH0 NG G R AW0 N D/
noun
  1. 1

    (figuratively) A situation or thing that allows new ideas, methods, or hypotheses to be tried out.

  2. 2

    A location set up for the testing of vehicles, machinery, agricultural techniques, etc. to ensure that they work as intended.

  3. 3

    A military site that is used for testing weapons.

  4. 4

    (figuratively) A situation or problem that allows people to test how good they are.