The name Aonach Mòr implies that the mountain is bigger than its close neighbour to the south, Aonach Beag (small ridge), to which it is linked by a high bealach. However, the names refer to the relative bulk of the mountains when seen from the glen, rather than their altitude above sea level; the summit of Aonach Mòr is in fact lower than the summit of Aonach Beag.