Webster's Revised Unabridged Dictionary · 1913

Concha

Concha (kon"kȧ) , noun

[Late Latin (in sense 1), from Latin concha. See Conch.]

1.
(Architecture) The plain semidome of an apse; sometimes used for the entire apse.
2.
(Anatomy) The external ear; esp. the largest and deepest concavity of the external ear, surrounding the entrance to the auditory canal.