Definition of "beak" []

• The horny, projecting structure forming the mandibles of a bird, especially one that is strong, sharp, and useful in striking and tearing; a bill. (noun)
• A similar structure in other animals, such as turtles, insects, or fish. (noun)
• A usually firm, tapering tip on certain plant structures, such as some seeds and fruits. (noun)
• A beaklike structure or part, as: (noun)
• The spout of a pitcher. (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.

• "Size, shape, and strength of chick beak is impacted when the gene is manipulated."
• "As the Yoon paper states, you have this large diversity of finch species marked off by variations in beak size."
• "However, this only works when the base of the beak is wet."