Meaning & Definition of word "Thumb"

noun:

• 1. The short, thick first digit of the human hand, which is opposable to the other four digits.
  • Example: He raised his thumb in approval.
• 2. A similar digit in other animals or in certain objects.
  • Example: The monkey's thumb helped it grip the branch securely.
• 3. A projection or protuberance resembling a thumb.
  • Example: The rock formation had a thumb-like shape.

verb:

• 1. To press, move, or touch something with the thumb.
  • Example: She thumbed through the pages of the book.
• 2. To give a signal of approval or disapproval by raising or lowering the thumb.
  • Example: He thumbed up to indicate that everything was okay.