Derived from the Irish "cathair", meaning a stone fort or enclosure, it is a placename found scattered across Ireland wherever early medieval communities built their circular stone walls and settled into the landscape. That the townland preserves this name at all suggests the enclosure here was substantial enough, or significant enough, to define the place in the memory of those who lived around it.

Stone enclosures of this kind, sometimes called cahers or cashels, were typically built during the early medieval period, roughly between the fifth and twelfth centuries, and served as farmsteads or the defended residences of local lords. Their walls, often dry-stone and several metres thick, enclosed a central living area and sometimes smaller outbuildings. The example recorded at Caher, Co. Mayo, sits within a county that contains a remarkable density of such monuments, from the great stone forts of the Atlantic coast to humbler enclosures tucked into bogland and hillside. Beyond its classification as an enclosure and its location in this Mayo townland, the specific details of this particular site remain largely undocumented in publicly available records.