The Collaborative International Dictionary of English v.0.48:
Solipsism \So*lip"sism\, n. [L. solus alone + ipse self.] 1. (Ethics) Egotism. --Krauth-Fleming. [1913 Webster] 2. (Metaph.) Egoism. --Krauth-Fleming. [1913 Webster]WordNet (r) 3.0 (2006):
solipsism n 1: (philosophy) the philosophical theory that the self is all that you know to exist