The Collaborative International Dictionary of English v.0.48:
Subcutaneous \Sub`cu*ta"ne*ous\, a. Situated under the skin; hypodermic. -- Sub`cu*ta"ne*ous*ly, adv. [1913 Webster] Subcutaneous operation (Surg.), an operation performed without opening that part of the skin opposite to, or over, the internal section. [1913 Webster]WordNet (r) 3.0 (2006):
subcutaneously adv 1: below the skin; "inject subcutaneously"