Definition of "porthole" [port•hole]

• Nautical A small, usually circular window in a ship's side. (noun)
• An opening in a fortified wall; an embrasure. (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.

• "The porthole is the only thing that didn't get messed up."
• "An 80-year-old man on a flight from the Philippine capital of Manila to the island of Cebu attempted to break a porthole window during the flight with his cane and leave the aircraft,"
• "The round thing behind the porthole is a carry point for a life preserver."