The Collaborative International Dictionary of English v.0.48:
Shinplaster \Shin"plas`ter\, n. Formerly, a jocose term for a bank note greatly depreciated in value; also, for paper money of a denomination less than a dollar. [U. S.] [1913 Webster] ShintoWordNet (r) 3.0 (2006):
shinplaster n 1: paper money of little value issued on insufficient security