\A*pot"o*me\, n. [Gr. ? a cutting off, fr. ? to cut off;
? from + ? to cut.]
1. (Math.) The difference between two quantities
   commensurable only in power, as between [root]2 and 1, or
   between the diagonal and side of a square.
2. (Mus) The remaining part of a whole tone after a smaller
   semitone has been deducted from it; a major semitone.
   [Obs.]