The Collaborative International Dictionary of English v.0.48:

Manichord \Man"i*chord\, Manichordon \Man`i*chor"don\, [L.
   monochordon, Gr. ?; -- so called because it orig. had only
   one string. See Monochord.] (Mus.)
   The clavichord or clarichord; -- called also dumb spinet.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Clarichord \Clar"i*chord\, n. [F. clatocorde, fr.L. clarus clear
   + chorda string. See Chord.]
   A musical instrument, formerly in use, in form of a spinet;
   -- called also manichord and clavichord.
   [1913 Webster]