grandmother n.

a special use of grand (adj.) in genealogical compounds, originally with the sense of "a generation older than," first attested c. 1200, in Anglo-French graund dame "grandmother," also grandsire (late 13c.), from such use of Old French grand-, which perhaps is modeled on Latin avunculus magnus "great uncle." The partly-Englished grandmother, grandfather are from 15c. Other such words in European languages are formed with the adjectives for "old" or "best" (Danish bedstefar) or as diminutives or pet names (Greek pappos, Welsh taid). The French formation also is the model for such words in German and Dutch. Spanish abuelo is from Latin avus "grandfather" (from PIE *awo- "adult male relative other than the father;" see uncle), via Vulgar Latin *aviolus, a diminutive or adjective substitution for the noun.

The extension of the sense to corresponding relationships of descent, "a generation younger than" (grandson, granddaughter) is from Elizabethan times. The inherited PIE root, *nepot- "grandchild" (see nephew) has shifted to "nephew; niece" in English and other languages (Spanish nieto, nieta). Old English used suna sunu ("son's son"), dohtor sunu ("son's daughter").

"female parent, a woman in relation to her child," Middle English moder, from Old English modor, from Proto-Germanic *mōdēr (source also of Old Saxon modar, Old Frisian moder, Old Norse moðir, Danish moder, Dutch moeder, Old High German muoter, German Mutter), from PIE *mater- "mother" (source also of Latin māter, Old Irish mathir, Lithuanian motė, Sanskrit matar-, Greek mētēr, Old Church Slavonic mati), "[b]ased ultimately on the baby-talk form *mā- (2); with the kinship term suffix *-ter-" [Watkins]. Spelling with -th- dates from early 16c., though that pronunciation is probably older (see father (n.)).

Sense of "that which has given birth to anything" is from late Old English; as a familiar term of address to an elderly woman, especially of the lower class, by c. 1200.

Mother Nature as a personification is attested from c. 1600; mother earth as an expression of the earth as the giver of life is from 1580s. Mother tongue "one's native language" is attested from late 14c. Mother country "a country in relation to its colonies" is from 1580s. Mother-love "such affection as is shown by a mother" is by 1854. Mother-wit "native wit, common sense" is from mid-15c.

Mother of all ________ (1991), is Gulf War slang, from Saddam Hussein's use in reference to the coming battle; it is an Arabic idiom (as well as an English one), for instance Ayesha, second wife of Muhammad, is known as Mother of Believers; the figure is attested in English in 19c. (Virginia is called mother of commonwealths from 1849). Mother Carey's chickens is late 18c. sailors' nickname for storm petrels, or for snowflakes.