Archaic and chiefly British ecclesiastical usage; countable.
Definitions
(historical, chiefly British) A parish, church, or chapel exempt from the jurisdiction of the diocese in which it lies and instead subject directly to the Crown or an archbishop.
Westminster Abbey is a royal peculiar that answers directly to the monarch.
(archaic) A special privilege, property, or exclusive right belonging to a particular person or group.
The right to hunt in the surrounding forest was once the peculiar of the estate's lord.