tumulus(n = noun.artifact) barrow, burial mound, grave mound - (archeology) a heap of earth placed over prehistoric tombs;
is a kind of hill, mound

   An artificial hillock, especially one raised over a grave, particularly over the graves of persons buried in ancient times; a barrow. [1913 Webster]

tumulus, n. (pl. tumuli) an ancient burial mound or barrow.

Derivative:
tumular adj.

Etymology:
L f. tumere swell

N  interment, burial, sepulture, inhumation, obsequies, exequies, funeral, wake, pyre, funeral pile, cremation, funeral, funeral rite, funeral solemnity, kneel, passing bell, tolling, dirge, cypress, orbit, dead march, muffled drum, mortuary, undertaker, mute, elegy, funeral, funeral oration, funeral sermon, epitaph, graveclothes, shroud, winding sheet, cerecloth, cerement, coffin, shell, sarcophagus, urn, pall, bier, hearse, catafalque, cinerary urn, grave, pit, sepulcher, tomb, vault, crypt, catacomb, mausoleum, Golgotha, house of death, narrow house, cemetery, necropolis, burial place, burial ground, grave yard, church yard, God's acre, tope, cromlech, barrow, tumulus, cairn, ossuary, bone house, charnel house, dead house, morgue, lich gate, burning ghat, crematorium, crematory, dokhma, mastaba, potter's field, stupa, Tower of Silence, sexton, gravedigger, monument, cenotaph, shrine, grave stone, head stone, tomb stone, memento mori, hatchment, stone, obelisk, pyramid, exhumation, disinterment, necropsy, autopsy, post mortem examination, zoothapsis, burried, burial, funereal, funebrial, mortuary, sepulchral, cinerary, elegiac, necroscopic, in memoriam, post obit, post mortem, beneath the sod, hic jacet, ci-git, RIP, requiescat in pace, the lone couch of his everlasting sleep, without a grave- unknell'd, uncoffin'd, and unknown, in the dark union of insensate dust, the deep cold shadow of the tomb, Special Vitality.