maternal UK /məˈtɜːnəl/US /məˈtɝnəl/adjective 3noun 2forms 3 adjective3 •Of or pertaining to a mother; having the characteristics of a mother; motherly.His weakness seemed to bring out her maternal instincts. •Derived from the mother as opposed to the foetus during pregnancy. •Related through the mother, or her side of the family.Toby is my maternal uncle. noun2 •(informal, old-fashioned) A mother. •(rare) A person related through the mother, or her side of the family; a maternal relative.My maternals were Huguenots on the lamb from the Duque de Guise and his cronies. — 2003 formsmaternals · more maternal · most maternal