The Collaborative International Dictionary of English v.0.48:

Tendinous \Ten"di*nous\, a. [Cf. F. tendineux.]
   1. Pertaining to a tendon; of the nature of tendon.
      [1913 Webster]

   2. Full of tendons; sinewy; as, nervous and tendinous parts
      of the body.
      [1913 Webster]

WordNet (r) 3.0 (2006):

tendinous
    adj 1: consisting of tendons or resembling a tendon [syn:
           tendinous, sinewy]