The Collaborative International Dictionary of English v.0.48:

Tendosynovitis \Ten`do*syn`o*vi"tis\, n. [NL. See Tendon, and
   Synovitis.]
   See Tenosynovitis.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tendosynovitis
    n 1: inflammation of a tendon and its enveloping sheath [syn:
         tenosynovitis, tendosynovitis, tendonous synovitis]