NOUN (1)

1. a bishop having jurisdiction over a diocese;


ADJECTIVE (1)

1. belonging to or governing a diocese;

The Collaborative International Dictionary of English v.0.48:

Diocesan \Di*oc"e*san\ (?; 277), a. [LL. dioecesanus: cf. F.
   dioc['e]sain.]
   Of or pertaining to a diocese; as, diocesan missions.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Diocesan \Di*oc"e*san\, n.
   1. A bishop, viewed in relation to his diocese; as, the
      diocesan of New York.
      [1913 Webster]

   2. pl. The clergy or the people of a diocese. --Strype.
      [1913 Webster]

WordNet (r) 3.0 (2006):

diocesan
    adj 1: belonging to or governing a diocese
    n 1: a bishop having jurisdiction over a diocese