uberrima fides

noun | \ yü-ˈber-i-mə-ˈfī-ˌdēz, ü-ˈber-ē-ˌmä-ˈfē-ˌdās \ | uber·ri·ma fi·des

1. : utmost or perfect good faith acted in uberrima fides

   Note: The terms uberrima fides and uberrimae fidei, although grammatically distinct in Latin, are often used interchangeably in English.