Decachord \Dec"a*chord\, Decachordon \Dec`a*chor"don\, n. [Gr. deka`chordos tenstringed; de`ka ten + chordj` a string.] 1. An ancient Greek musical instrument of ten strings, resembling the harp. [1913 Webster] 2. Something consisting of ten parts. --W. Watson. [1913 Webster]