What is "abban"

Abbán moccu Corbmaic (d. 520?), also Eibbán or Moabba, is a saint in Irish tradition. He was associated, first and foremost, with Mag Arnaide (Moyarney or Adamstown, near New Ross, Co. Wexford) and with Cell Abbáin (Killabban, County Laois). His cult was, however, also connected to other churches elsewhere in Ireland, notably that of his alleged sister Gobnait.