Definition of "three-decker" [three•-deck•er]

• A ship having three decks, especially one of a class of sail-powered warships with guns on three decks. (noun)
• Something with three levels or layers, as: (noun)
• A three-story apartment building. (noun)
• A sandwich having three slices of bread. (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.

• "Later that afternoon I turned ontoPearl Streetand noticed a woman smoking on the first floor of a three-decker tenement."
• "Annie had lived with her Polish grandmother in another dingy three-decker on the next corner."
• "The huge three-decker Sky Queen, a completely equipped flying laboratory, had been Tom's first major invention."