Bernard Tanguy ː Coatrevar (= Coatreven), 1182; Coytrevan, Coytrevant, Quoytrevan, 1330; Coetrevan, 1381; Quoetrevan, fin XIVt ktv; Coetrevan, 1427, 1437, 1543; Quoitrevan, 1486; Coatréven, 596; Coatreven, 1600;