Kilnagalliagh derives from the Irish Coill na gCailleach, meaning the wood of the hags or old women, a name with associations elsewhere in Ireland to supernatural female figures, boundary places, or simply to a folklore that has long since gone quiet. That a recorded earthwork sits within this particular townland gives the site a certain atmosphere, even before any spade has been described.

Earthworks as a category cover a broad range of field monuments. The term can apply to anything from a raised ringfort enclosure, a bank and ditch surrounding a former farmstead, to a more ceremonial or funerary mound, a linear boundary feature, or the eroded remains of a medieval settlement. Without more detailed survey information having been published for this specific site, its precise form and date remain unclear. Clare as a county is unusually dense with early medieval and prehistoric remains, from the limestone karst of the Burren, where ancient field walls and wedge tombs emerge from bare rock, to the gentler inland pastures where earthen monuments tend to survive under grass. An earthwork in this landscape could plausibly belong to almost any period from the Neolithic onward.