The Collaborative International Dictionary of English v.0.48:

Melibean \Mel`i*be"an\, Meliboean \Mel`i*b[oe]"an\, a. [From L.
   Meliboeus, one of the interlocutors in Virgil's first
   Eclogue.] (Rhet.)
   Alternately responsive, as verses.
   [1913 Webster]