Definition of "thumb" []

• The short thick digit of the human hand, next to the index finger and opposable to each of the other four digits. (noun)
• A corresponding digit in other animals, especially primates. Also called pollex. (noun)
• The part of a glove or mitten that covers the thumb. (noun)
• Architecture An ovolo. (noun)
• To scan (written matter) by turning over pages with or as if with the thumb. (verb-transitive)

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.

• "Medical science has proved that there is such a thing as a "thumb centre" in the brain and any pressure or disease in that part of the brain _shows its effect in the thumb_."
• "_] An expression of contempt or insult, which consisted in thrusting the thumb between two of the closed fingers, or into the mouth; whence _Bite the thumb_."
• "The last photo in the thumb is his – great shot …."