barrow (n.1) Look up barrow at Dictionary.com
"flat, rectangular frame with projecting handles for carrying a load," c. 1300, barewe, probably from an unrecorded Old English *bearwe "basket, barrow," from beran "to bear, to carry," from PIE root *bher- (1) "to carry." The original (hand-barrow) had no wheel and required two persons to carry it.
barrow (n.2) Look up barrow at Dictionary.com
"mound, hill, grave-mound," Old English beorg (West Saxon), berg (Anglian) "barrow, mountain, hill, mound," from Proto-Germanic *bergaz (source also of Old Saxon, Old Frisian, Old High German berg "mountain," Old North bjarg "rock"), from PIE root *bhergh- (2) "high, elevated" (source also of Old Church Slavonic bregu "mountain, height;" Old Irish brigh "mountain;" Welsh bera "stack, pyramid;" Sanskrit b'rhant "high," brmhati "strengthens, elevates;" Avestan brzant- "high," Old Persian bard- "be high;" Greek Pergamos, name of the citadel of Troy). Obsolete by c. 1400 except in place-names and southwest England dialect; revived by modern archaeology.
In place-names used of small continuously curving hills, smaller than a dun, with the summit typically occupied by a single farmstead or by a village church with the village beside the hill, and also of burial mounds. [Cambridge Dictionary of English Place-Names]
Meaning "mound erected over a grave" was in late Old English. Barrow-wight first recorded 1869 in Eirikr Magnusson and William Morris's translation of the Icelandic saga of Grettir the Strong.