Irish academic Paul Tempan notes in the Irish Hill and Mountain Names database that Mangerton is most likely a translation of , meaning the long-haired. Tempan discussed the possibility that an alternative interpretation of may be worth considering, as it could be the noun with the suffix ach. Tempan notes P. S. Dinneen's Foclóir Gaedhilge agus Béarla—Irish-English Dictionary (1927), defines as movement or shaking. Thus the adjective (not listed in any dictionary) could mean moving, shaking, or quaking, which could refer to the physical movement of Mangerton bog prevalent on the southern slopes, or could be understood figuratively as meaning vacillating or fickle.