aptronym is a coinage of Franklin P. Adams (1881-1960), a member of the Algonquin Round Table. there is also a word which comes directly from Greek which means virtually the same thing: euonym. you're more apt to remember the former.

http://www.m-w.com/lighter/name/aptronym.htm

http://www.pbs.org/wnet/americanmasters/database/algonquin_round_table.html