The Collaborative International Dictionary of English v.0.48:

Medial \Me"di*al\, n. (Phonetics)
   See 2d Media.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Medial \Me"di*al\ (m[=e]"d[i^]*al), a. [L. medialis, fr. medius
   middle: cf. F. m['e]dial. See Middle.]
   Of or pertaining to a mean or average; mean; as, medial
   alligation.
   [1913 Webster]

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]

WordNet (r) 3.0 (2006):

medial
    adj 1: dividing an animal into right and left halves [syn:
           medial, median]
    2: relating to or situated in or extending toward the middle
       [syn: median, medial]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "medial":
   amidships, average, banal, center, centermost, central, common,
   core, equatorial, equidistant, fair, fairish, halfway, indifferent,
   intercurrent, interior, interjacent, intermediary, intermediate,
   intervenient, intervening, mean, median, mediocre, mediterranean,
   medium, mesial, mesne, mezzo, mid, middle, middle-of-the-road,
   middlemost, middling, midland, midmost, midships, midway, moderate,
   normal, nuclear, ordinary, routine, standard, usual