What is "meubred"

St Meubred, Mewbred or Mebbred, is a local Cornish saint with a single dedication, the church of St Meubred, Cardinham, in the Diocese of Truro. William Worcestre names him as the son of an Irish king who became a Cornish hermit. He was a contemporary of St Mannacus and St Wyllow. An image of him carrying an extra head in his hands is included in a stained glass window in the church of St Neot alongside St Mabyn.