The name alone does a great deal of work. Across Ireland, such place-names tend to mark natural rock formations, whether a distinctive outcrop, a flat-topped stone, or a depression worn into a boulder, that local tradition has attached to a figure of power or legend. The "Earl" in question is unspecified in surviving records, but in this part of Connacht the title would most naturally invoke the earls of Clanricarde, the Burke family who dominated much of Galway from the late medieval period onward and left their mark on the landscape in place-names, ruins, and folklore alike.

Derrybrien itself sits in the Slieve Aughty uplands, a stretch of boggy, forested hills that straddle the Galway and Clare border. It is quiet, relatively remote country, and the kind of place where named stones and natural seats tend to accumulate association over generations without ever being formally recorded. Whether the Earl's Chair is a glacial erratic, a natural rock shelf, or something more deliberately shaped is not currently documented in accessible archaeological records, which means the site sits in that not uncommon category of named Irish monuments whose physical character remains tantalisingly undescribed.