"walking with heavy steps," 1839, probably via French, a modern scientific compound from Latin gravis "heavy" (from PIE root *gwere- (1) "heavy") + gradi "to walk" (from PIE root *ghredh- "to walk, go").
graver
Graves' disease
gravestone
graveyard
gravid
gravigrade
gravimeter
gravitas
gravitate
gravitation
gravitational