An airplane with wings placed above each other in three levels. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "triplane" in a sentence
"The triplane was a single-seater with a rotary engine and an open cockpit; it had RFC roundels on the fuselage."
"His planes included: the Fokker Eindecker and the Fokker D.R. 1, which was the triplane made famous by Baron Manfred von Richthofen, also known as The Red Baron."
"Not by another ace, but when Richthofen made a rookie mistake and flew his red (note that's red) triplane over Brit anti-aircraft gunners while single mindedly pursuing another fighter."