"soft tissue found in the interior of bones," late 14c., from Old English mearg "marrow," earlier mærh, from Proto-Germanic *mazga- (source also of Old Norse mergr, Old Saxon marg, Old Frisian merg, Middle Dutch march, Dutch merg, Old High German marg, German Mark "marrow"), from PIE *mozgo- "marrow" (source also of Sanskrit majjan-, Avestan mazga- "marrow," Old Church Slavonic mozgu, Lithuanian smagenės "brain"). Figurative sense of "inmost or central part, inner substance, essence" is attested from mid-14c.
gourd fruit, 1640s, shortened borrowing from Narraganset (Algonquian) askutasquash, literally "the things that may be eaten raw," from askut "green, raw, uncooked" + asquash "eaten," in which the -ash is a plural affix (compare succotash).
1610s, "act of squashing," from squash (v.). The racket game called by that name 1899; earlier (1886) it was the name of the soft rubber ball used in it.
"tumor composed of bone-marrow cells," 1848, from Greek myelos "marrow" (a word of unknown origin) + -oma.
1915 in English cookery books, 1910 in travel books about Italy as an Italian word (defined as "an odd kind of little squash, very tender and palatable"), from Italian, plural of zucchino, diminutive of zucca "gourd, squash," perhaps from Late Latin cucutia, which is of unknown origin.
hindmost segment of the brain, 1670s, from Latin medulla, literally "marrow," also "pith of plants," a word of uncertain origin, but probably from PIE *smer-u- "marrow" (source also of Old Irish smiur, Welsh mer "marrow"), perhaps influenced by medius "middle." The word was used in the Latin senses in Middle English. Related: Medullar; medullary.
late 14c., marybones (late 13c. as a surname), "bone containing fat or marrow," from marrow + bone (n.). A poetic Old English word for "bone" was mearhcofa "marrow-chamber." Later generally of any large bone. The conjecture that it is a corruption of Mary-bones, in allusion to the reverence paid to the Virgin Mary by kneeling "is absurd" [Century Dictionary]; nonetheless, marrowbones is used especially to mean "the bones of the knees" (1530s). To ride in the marrow-bone coach was one of many terms in old slang for "to go on foot."
"hard seed," 1841, from Dutch pit "kernel, seed, marrow," from Middle Dutch pitte, ultimately from Proto-Germanic *pithan-, source of pith (q.v.).