trilogue

/T R AY1 L AO1 G/
noun
  1. 1

    A discourse or colloquy by three people.

  2. 2

    (European Union) An informal tripartite meeting attended by representatives of the European Parliament, the Council of the European Union, and the European Commission.

Source: https://en.wiktionary.org/wiki/trialogue, https://en.wiktionary.org/wiki/trilogue