also matriclinous, "resembling the mother rather than the father," 1911, from matri- "mother" + Latinized form of Greek klinein "to lean" (from PIE root *klei- "to lean") + -ous.

"mother or woman who heads a family or tribe," c. 1600, from matri- "mother, woman" + -arch, abstracted from patriarch, ultimately from Greek arkhein "to rule" (see archon).

"tough outer membrane surrounding the brain and the spinal cord," c. 1400, from Medieval Latin dura mater cerebri, literally "hard mother of the brain," a loan-translation of Arabic umm al-dimagh as-safiqa, literally "thick mother of the brain." "In Arabic, the words 'father,' 'mother,' and 'son' are often used to denote relationships between things" [Klein].

"government by a mother or mothers; form of social organization in which the mother is the head of the family and the descendants are reckoned through the maternal side," formed in English 1881 from matriarch + -y (4) and "patterned after patriarchy" [Barnhart].

1590s, "type of shellfish that yields mother-of-pearl," from French nacre (Old French nacaire, 14c.), from Italian naccaro (now nacchera), possibly from Arabic naqur "hunting horn" (from nakara "to hollow out"), in reference to the shape of the mollusk shell. Meaning "mother-of-pearl" is from 1718. The French adjectival form nacré was applied in English to decorative objects iridescent like mother of pearl (1895).

pet word for "mother," 1823, short for mummy (see mamma). In British sociology, used from 1957 in reference to "the working class mother as an influence in the lives of her children." Also sometimes a vulgar corruption of madam or ma'am.