Old English græf "grave, ditch, cave," from Proto-Germanic *graban (cf. Old Saxon graf, Old Frisian gref, Old High German grab "grave, tomb;" Old Norse gröf "cave," Gothic graba "ditch"), from PIE root *ghrebh- "to dig, to scratch, to scrape" (cf. Old Church Slavonic grobu "grave, tomb"); related to grafan "to dig" (see grave (v.)).
"The normal mod. representation of OE. græf would be graff; the ME. disyllable grave, from which the standard mod. form descends, was prob. due to the especially frequent occurrence of the word in the dat. (locative) case. [OED]From Middle Ages to 17c., they were temporary, crudely marked repositories from which the bones were removed to ossuaries after some years and the grave used for a fresh burial. "Perpetual graves" became common from c.1650. To make (someone) turn in his grave "behave in some way that would have offended the dead person" is first recorded 1888.
1540s, from Middle French grave (14c.), from Latin gravis "weighty, serious, heavy, grievous, oppressive," from PIE root *gwere- "heavy" (cf. Sanskrit guruh "heavy, weighty, venerable;" Greek baros "weight," barys "heavy in weight," often with the notion of "strength, force;" Old English cweorn "quern;" Gothic kaurus "heavy;" Lettish gruts "heavy"). Greek barys (opposed to kouphos) also was used figuratively, of suffering, sorrow, sobbing, and could mean "oppressive, burdensome, grave, dignified, impressive." The noun meaning "accent mark over a vowel" is c.1600, from French.
"to engrave," Old English grafan (medial -f- pronounced as "v" in Old English; past tense grof, past participle grafen) "to dig, carve, dig up," from Proto-Germanic *grabanan (cf. Old Norse grafa, Old Frisian greva, Dutch graven, Old High German graban, German graben, Gothic graban "to dig, carve"), from the same source as grave (n.). Its Middle English strong past participle, graven, is the only part still active, the rest of the word supplanted by its derivative, engrave.
Serious or dangerous, as a symptom or disease.
Among the ancient Hebrews graves were outside of cities in the open field (Luke 7:12; John 11:30). Kings (1 Kings 2:10) and prophets (1 Sam. 25:1) were generally buried within cities. Graves were generally grottoes or caves, natural or hewn out in rocks (Isa. 22:16; Matt. 27:60). There were family cemeteries (Gen. 47:29; 50:5; 2 Sam. 19:37). Public burial-places were assigned to the poor (Jer. 26:23; 2 Kings 23:6). Graves were usually closed with stones, which were whitewashed, to warn strangers against contact with them (Matt. 23:27), which caused ceremonial pollution (Num. 19:16). There were no graves in Jerusalem except those of the kings, and according to tradition that of the prophetess Huldah.