groove n.

"excavation in earth for reception of a dead body," Old English græf "grave; ditch, trench; cave," from Proto-Germanic *grafa-/graba- (source also of Old Saxon graf, Old Frisian gref, Old High German grab "grave, tomb;" Old Norse gröf "cave," Gothic graba "ditch"), cognate with Old Church Slavonic grobu "grave, tomb," and perhaps from a PIE root *ghrebh- (2) "to dig, to scratch, to scrape," related to Old English grafan "to dig" (see grave (v.)). Or perhaps a substratum word in Germanic and Balto-Slavic.

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. Grave-side (n.) is from 1744. Grave-robber attested from 1757. To make (someone)turn in his grave "behave in some way that would have offended the dead person" is first recorded 1888.

1850, "pertaining to a groove," from groove (n.) + -y (2). The slang sense of "first-rate, excellent" is by 1937, American English, from jazz slang phrase in the groove (1932) "performing well" (without grandstanding). As teen slang for "wonderful," it dates from c. 1941; popularized mid-1960s, out of currency by 1980.

GROOVY: Good, nice. "That's groovy." Came in around 1966 and now is used mainly in soft-drink commercials and ads for suburban boutiques. [Mike Jahn, "Are You Hip?" Louisville, Ky. Courier-Journal, July 11, 1971]

The earlier colloquial figurative sense was "having a tendency to routine, inclined to a specialized and narrow way of life or thought" (1882). Related: Grooviness.