The B'Nar (English translation, "the mourning") was a Talarian ritual.
It consisted of a high-pitched shriek and rocking back and forth for a considerable time-span. Jono performed the B'Nar while being treated in sickbay aboard the USS Enterprise-D and later when he was separated from the other teenage Talarians rescued from a disabled Talarian observation craft. (TNG: "Suddenly Human")