The derivation and meaning of the word Labarum or Laborum, which is employed by Gregory Nazianzen, Ambrose, Prudentius, etc., still remain totally unknown, in spite of the efforts of the critics, who have ineffectually tortured the Latin, Greek, Spanish, Celtic, Teutonic, Illyric, Armenian, etc in search of an etymology. See Ducange, in Gloss Med. and infim. Latinitat. sub voce Labarum, and Godefroy, ad Cod. Theodos. tom. ii. p. 143.