From ᡨᠣᡴᡨᠣᡥᠣ (toktoho, “fixed”) + ᡤᡳᠰᡠᠨ (gisun, “words”), literally “fixed words”.
ᡨᠣᡴᡨᠣᡥᠣᡤᡳᠰᡠᠨ • (toktoho gisun)