McMahon clans
McMahon, also spelt MacMahon (older Irish orthography: Mac Mathghamhna; reformed Irish orthography: Mac Mathúna), were different Middle Age era Irish clans. Their name is derived from the Gaelic Mac Mathghamhna meaning 'son of the bear'. According to historian C. Thomas Cairney, the MacMahons were one of the chiefly families of the Dal gCais or Dalcassians who were a tribe of the Erainn who were the second wave of Celts to settle in Ireland between about 500 and 100 BC.