History of Manchester
According to Oxford University Press, Manchester derived its name from Mamucium, the Roman name for the 1st century-settlement and fort. Mamucium itself is a Latinised form of the Celtic meaning "breast-shaped hill".
Bryn, Greater Manchester
The name "Bryn" is most likely derived from Cumbric "*brïnn", meaning 'hill' (Welsh "bryn"). Alternatively, the name may be derived directly from the Welsh equivalent, possibly reflecting Welsh settlement in the 12th century. A third explanation is that the name is derived from Old English "bryne", 'burning, fire', suggestive of land cleared by burning.