Definition of "keel" []

• Nautical The principal structural member of a ship, running lengthwise along the center line from bow to stern, to which the frames are attached. (noun)
• Nautical A ship. (noun)
• A structure, such as the breastbone of a bird, that resembles a ship's keel in function or shape. (noun)
• The principal structural member of an aircraft, resembling a ship's keel in shape and function. (noun)
• A pair of united petals in certain flowers, as those of the pea. (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.

• "But the responsibility of keeping the Canadian economy on an even keel is not one that should be left primarily or even mainly to the financial system."
• "Now, in some of our shipyards these vessels are being launched only ten days after the keel is laid and they are fully ready to load cargo and sail to the aid of our fighting forces only fourteen days after they are launched."
• "Her fin keel struck bottom, and her main topmast lurched and shivered as if about to come down upon our heads."