It derives from the Irish cathairín, meaning "little cathair", and a cathair is a type of stone-walled enclosure associated with early medieval settlement, particularly in Munster. The diminutive suffix suggests something modest in scale, perhaps a small farmstead or a subsidiary enclosure attached to a larger complex, the kind of structure that sheltered a family and their animals within a roughly circular or oval boundary of dry-laid stone.

Enclosures of this type are scattered across the Kerry landscape in considerable numbers, many of them unexcavated and poorly understood. They range from the elaborate, multivallate stone forts such as those on the Dingle Peninsula, to simple single-walled enclosures that survive only as low, grass-covered banks. The placename Cahereen itself appears in several townlands across County Kerry, each instance likely marking a spot where such a structure once stood visibly enough to define the local geography and pass into common use. Without more detailed fieldwork records for this particular site, its precise form, date, and condition remain difficult to characterise, though the broader tradition it belongs to spans roughly the period from the early centuries AD through to the early medieval period.

What is certain is that the survival of the placename alone indicates the enclosure left a mark on the landscape legible enough for successive generations to carry forward. In parts of Kerry, these small stone enclosures are still visible as slight earthworks or tumbled wall lines, easy to miss without some knowledge of what to look for.