OE grafan to dig, carve ＜ Gmc raan (G graben) ← IE ghrebh-🔗⭐🔉

OE grafan to dig, carve ＜ Gmc raan (G graben) ← IE ghrebh- to dig, bury, scratch (Ch.Slav. greb I dig): cf. grave^１, groove, gravure grave^４ /gr:v ｜ grv, grv; F. gav/

研究社新英和大辞典 ページ 193582 での【G graben】単語。