middle mute

from The Collaborative International Dictionary of English v.0.48

Media \Me"di*a\, n.; pl. {Mediae} (-[=e]). [NL., fr. L. medius
   middle.]
   1. (Phonetics) One of the sonant mutes [beta], [delta],
      [gamma] (b, d, g), in Greek, or of their equivalents in
      other languages, so named as intermediate between the
      tenues, [pi], [tau], [kappa] (p, t, k), and the aspiratae
      (aspirates) [phi], [theta], [chi] (ph or f, th, ch). Also
      called {middle mute}, or {medial}, and sometimes {soft
      mute}.
      [1913 Webster]