The Collaborative International Dictionary of English v.0.48:

Causerie \Cause`rie"\, n. [F., fr. causer to chat.]
   Informal talk or discussion, as about literary matters; light
   conversation; chat.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

causerie
    n 1: light informal conversation for social occasions [syn:
         chitchat, chit-chat, chit chat, small talk, gab,
         gabfest, gossip, tittle-tattle, chin wag, chin-
         wag, chin wagging, chin-wagging, causerie]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "causerie":
   article, chat, chin, coze, cozy chat, descant, discourse,
   discussion, disquisition, dissertation, essay, etude, examination,
   excursus, exposition, feature, first approach, friendly chat, gam,
   heart-to-heart talk, homily, introductory study, little talk,
   lucubration, memoir, monograph, morceau, note, outline, pandect,
   paper, paragraph, piece, preliminary study, prolegomenon, prose,
   rap, research paper, screed, sketch, special article, study,
   survey, talk, term paper, tete-a-tete, theme, thesis, tract,
   tractate, treatise, treatment, visit, yarn