In Irish placename convention, "rath" denotes a ringfort, the circular earthen enclosure that served as a farmstead and family compound during the early medieval period, roughly between the fifth and twelfth centuries. That a townland should carry the ringfort's name into the present is itself a kind of quiet persistence, the landscape holding a memory long after the structure that prompted it has settled back into the ground.

Ringforts of this type, known as raths, were typically defined by one or more banks of earth and accompanying ditches, enclosing a domestic space used for housing, animal husbandry, and storage. They were the most common form of rural settlement in early medieval Ireland, and Clare has a considerable concentration of them. The name Rathcahaun likely combines "rath" with a personal name or descriptor, a naming pattern found across the country that once identified whose enclosure this was or what distinguished it locally. Beyond the placename itself, detailed records specific to this site have not yet been made publicly available.