
Scottish (of Norman origin): from the Breton personal name Cumin (Old Breton Cunmin from con- ‘hound’ with an uncertain second element perhaps min ‘edge’ which is found in other Breton personal names). There seems to be no basis for historians' insertion of the preposition de in this surname from the mistaken inference that it was a locative name from Comines in Nord (France). Irish: Anglicized form of Gaelic Mac Cuimín (or Ó Cuimín) ‘son (or ‘descendant’) of Cuimín’ a personal name formed from a diminutive of cam ‘crooked’. There was a 7th-century abbot of Iona named Cumin. In Scotland this Irish surname became confused with the Norman name (see 1 above).
Source: Dictionary of American Family Names 2nd edition, 2022