The Collaborative International Dictionary of English v.0.48:
Discourser \Dis*cours"er\, n.
1. One who discourse; a narrator; a speaker; an haranguer.
[1913 Webster]
In his conversation he was the most clear
discourser. --Milward.
[1913 Webster]
2. The writer of a treatise or dissertation.
[1913 Webster]
Philologers and critical discoursers. --Sir T.
Browne.
[1913 Webster]
Moby Thesaurus II by Grady Ward, 1.0:
35 Moby Thesaurus words for "discourser":
Boanerges, author, chalk talker, collocutor, colloquialist,
conversational partner, conversationalist, converser, descanter,
dialogist, disquisitor, essayist, expositor, expounder, homilist,
interlocutor, interlocutress, interlocutrice, interlocutrix,
lecturer, monographer, monographist, palaverer, parleyer,
praelector, preacher, pulpitarian, pulpiteer, reader, sermoner,
sermonist, sermonizer, talker, tractation, writer