GNU Collaborative International Dictionary of English

Found one definition

1.       
   Effendi (?), n., [Turk. efendi, fr. Modern Gr. , fr. Gr.  a chief. See Authentic.] Master; sir; -- a Turkish title of respect, applied esp. to a state official or man of learning, as one learned in the law, but often simply as the courtesy title of a gentleman.
   
   [Webster 1913 Suppl.]