The Collaborative International Dictionary of English v.0.48:
Departer \De*part"er\, n. 1. One who refines metals by separation. [Obs.] [1913 Webster] 2. One who departs. [1913 Webster]WordNet (r) 3.0 (2006):
departer n 1: someone who leaves [syn: departer, leaver, goer]