A name or title of Christ as the redeemer of the world, used in Tolkien’s Quenya translation of the Litany of Loreto prayer (VT44/12).
Possible Etymology: The first element is the genitive form mardo (“of the World”) of the noun mar(da), elsewhere translated as “dwelling” (PE17/107). This word (and its relative már) did not usually mean “World” in Tolkien’s later writings, but the earlier form ᴹQ. mar (mard-) was sometimes glossed “Earth” in his writing from the 1930s (LR/72, Ety/MBAR in Martano “Earthbuilder” and Endamar “Middle-earth”). Alternately, this may have been a restoration of the much earlier ᴱQ. marda “world”. In later writings, the usual Quenya word for “World” was Ambar.
The second element of this name is runando, apparently meaning “redeemer”.
Mardorunando noun "Redeemer of the world" (VT44:17). Unless the initial element mardo- is a distinct and otherwise unattested word for "world", it may be the genitive form of mar (mard-) "earth", q.v.