Sessão.
n.comité, commission, cellule, réunion, rassemblement, débat, soirée, séance, assemblée, congrès, séminaire, symposium, concile, vacation, spectacle
Vogais: eio
Consoantes: sssn
succession, sécession, scission, sein, scion, seine, sinon, saucisson, saison, son.