The Collaborative International Dictionary of English v.0.48:
Overplus \O"ver*plus\, n. [Over + L. plus more. See Plus, and cf. Surplus.] That which remains after a supply, or beyond a quantity proposed; surplus. --Shak. [1913 Webster] "The overplus of a great fortune." --Addison. [1913 Webster]WordNet (r) 3.0 (2006):
overplus n 1: extreme excess; "an embarrassment of riches" [syn: overplus, plethora, superfluity, embarrassment]