Deceiver's Cant was a secret language used exclusively among the cult of the Stranglers. It allowed them to operate and communicate with each other without revealing their presence to non-cult members. The language was used by the Stranglers throughout the Books of the South and the Books of Glittering Stone.
In Soldiers Live, the Khadidas approached the chief Strangler jamadar, Narayan Singh, and conversed with him in Deceiver's Cant. He used the breathy language to assure Narayan that he was the favorite servant of their goddess Kina... and then martyred him with a rumel.