compromisario
Compromisario is a legal term used mainly in civil law and arbitration to designate a person who is bound by a compromise (compromiso) or by an arbitration agreement to submit a dispute to resolution, usually by an arbitrator or arbitral panel. The term generally refers to a party that has consented to the settlement mechanism or to the arbitration process, and it can also extend to others named in the agreement who are thereby bound by its terms.
In practice, a compromis (the agreement to settle the dispute by arbitration or other means) creates obligations
The concept serves to distinguish the parties bound by the compromissum or compromis from the arbitrators