The Collaborative International Dictionary of English v.0.48:

Auricular \Au*ric"u*lar\ ([add]*r[i^]k"[-u]*l[~e]r), a. [LL.
   auricularis: cf. F. auriculaire. See Auricle.]
   1. Of or pertaining to the ear, or to the sense of hearing;
      as, auricular nerves.
      [1913 Webster]

   2. Told in the ear, i. e., told privately; as, auricular
      confession to the priest.
      [1913 Webster]

            This next chapter is a penitent confession of the
            king, and the strangest . . . that ever was
            auricular.                            --Milton.
      [1913 Webster]

   3. Recognized by the ear; known by the sense of hearing; as,
      auricular evidence. "Auricular assurance." --Shak.
      [1913 Webster]

   4. Received by the ear; known by report. "Auricular
      traditions." --Bacon.
      [1913 Webster]

   5. (Anat.) Pertaining to the auricles of the heart.
      [1913 Webster]

   Auricular finger, the little finger; so called because it
      can be readily introduced into the ear passage.
      [1913 Webster]

WordNet (r) 3.0 (2006):

auricular
    adj 1: of or relating to near the ear [syn: otic, auricular]
    2: relating to or perceived by or shaped like the organ of
       hearing; "my apprehension of words is auricular; I must hear
       what I read"- George Santayana; "an auricular confession";
       "an auricular appendage"
    3: pertaining to an auricle of the heart; "auricular
       fibrillation"

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "auricular":
   acoustic, audible, audile, audio, auditory, aural, between us,
   confidential, esoteric, hearing, in petto, inside,
   not for publication, off the record, otic, otological, otopathic,
   otoscopic, phonic, privileged, sealed, under privilege,
   unpublishable