The ordinal number of two hundred in counting order(adjective)
WordNet. Princeton University. 2010.
Use "200th" in a sentence
"Richard Dean Anderson To Guest Star in 200th Stargate SG-1"
"Colonel Richard Kemp, commander of British forces in Afghanistan between 2003 and 2004, called the 200th death "a very significant milestone"."
"Ebenezer Scrooge saw off many of the writer's best known and loved creations, including Miss Havisham, Sydney Carton, the Artful Dodger, Fagin, Nancy and Magwitch, in a Penguin Books poll commissioned to mark the 200th anniversary this week of Dickens's birth."