According to Adam Watson in the SMC Cairngorm guide, this is the only coloquial use of the term Grampian for a range of hills as used by local folk. Now of course the name has spread from geography textbooks to cover All the Mounth, and beyond. A similar expansion has occured with the term "Cairngorm".
Good to see this famous wee hill group
NJ9302 : The "Gramps", aka Kincorth Hill.