Valarauco ("k") noun "Demon of Might" (here vala- assumes its basic meaning "power, might"), Sindarin balrog(WJ:415). Pl. Valaraucar (sic, not -or) "Balrogs", apparently containing rauca (q.v.) as an alternative form of rauco "demon" (SA:val-, SA:rauco). Earlier forms from the "Qenya Lexicon" are Valcaraucë, Malcaraucë (q.v.), apparently abandoned in LotR-style Quenya.
Sindarin
Balrogs
Balrogs
Balrog is Sindarin for "Demon of Might" from bal-, "power" and raug, rog, "demon". The Quenya form Valarauko points to a possible Primitive Quendian form *balaraukô. In the earlier Etymologies, the word Balrog was derived from ñgwalaraukô, but this is inconsistent with Quenya Valarauko. A list of Old English equivalents of Elvish words, glosses Balrog as having the equivalent Bealuwearg and Bealubroga. As noted by Christopher Tolkien, the Old English word contains the elements bealu ("evil"; as in bale(ful)) and wearg ("wolf, outlaw") or broga ("terror").