The Collaborative International Dictionary of English v.0.48:

Avowee \A*vow`ee"\, n. [F. avou['e]. Cf. Advowee, Advocate,
   n.]
   The person who has a right to present to a benefice; the
   patron; an advowee. See Advowson.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

AVOWEE, eccl. law. An advocate of a church benefice.