1841, Leigh Hunt, Essays:Even fashions, otherwise convenient, as the trousers that have so long taken place of smallclothes, often perhaps owe their continuance to some general defect . . .
2000, George R. R. Martin, A Storm of Swords: A Song of Fire and Ice, ISBN 9780553106633, p. 701 (Google preview):One hand slid up her thigh and underneath her smallclothes.
2007 April 10, Tobias Hill, "School Stories," The Guardian (UK) (retrieved 17 May 2014)Are red socks a secret handshake, a mark of Etonhood, of an allegiance to the place both claimed and disclaimed? And having seen one pair I'm noticing them all over the place, a conspiracy of smallclothes.