The Collaborative International Dictionary of English v.0.48:

Tenonitis \Ten`o*ni"tis\, n. [NL., Gr. te`nwn tendon + -itis.]
   (Med.)
   Inflammation of a tendon.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Tenonitis \Ten`o*ni"tis\, n. [NL. See Tenonian, -itis.]
   Inflammation of the Tenonian capsule.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

tenonitis
    n 1: inflammation of a tendon [syn: tendinitis, tendonitis,
         tenonitis]