big shot

/B IH1 G SH AA1 T/
noun
  1. 1

    A person with a reputation of importance or power.

    โ€œThey stopped traffic so some big shot and his entourage could have the whole road to themselves.โ€

  2. 2

    A rare and significant chance to achieve fame or success.

Source: https://en.wiktionary.org/wiki/big%20shot