materfamilias n a female head of a family or tribe Usage(s) The Blackwells are overwhelming, especially the materfamilias, known as Maj (short for "Her Majesty"). The Blackwells are overwhelming, especially the materfamilias, known as Maj (short for "Her Majesty"). As before, the materfamilias-diarist has a husband, two children, temperamental Mademoiselle and house in the country on her hands. Synonym(s) matriarch