Source : Webster's Revised Unabridged Dictionary (1913)

Subclavian \Sub*cla"vi*an\, a. [Pref. sub- + L. clavis a key.
   See {Clavicle}.] (Anat.)
   Situated under the clavicle, or collar bone; as, the
   subclavian arteries.

Source : WordNet®

subclavian
     adj : situated beneath the clavicle