The Collaborative International Dictionary of English v.0.48:

Subsemitone \Sub*sem"i*tone\, n. (Mus.)
   The sensible or leading note, or sharp seventh, of any key;
   subtonic.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Subtonic \Sub*ton"ic\, n.
   1. (Phonetics) A subtonic sound or element; a vocal
      consonant, as b, d, g, n, etc.; a subvocal.
      [1913 Webster]

   2. (Mus.) The seventh tone of the scale, or that immediately
      below the tonic; -- called also subsemitone.
      [1913 Webster]