The Collaborative International Dictionary of English v.0.48:

Endermic \En*der"mic\, a. [Gr. ? in + ? skin.] (Med.)
   Acting through the skin, or by direct application to the
   skin.
   [1913 Webster]

   Endermic method, that in which the medicine enters the
      system through the skin, being applied either to the sound
      skin, or to the surface denuded of the cuticle by a
      blister.
      [1913 Webster]

WordNet (r) 3.0 (2006):

endermic
    adj 1: acting by absorption through the skin; "endermic
           ointment" [syn: endermic, endermatic]