thumb definition
The thumb is the first digit of the hand. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb is pollex (compare hallux for big toe), and the corresponding adjective for thumb is pollical.
uk â /Î¸Êm/ us â /Î¸Êm/. B1 the short, thick finger on the side of your hand that makes it possible to hold and pick things up easily. Examples. The thorn was embedded in her thumb. She hit her thumb with the hammer. I gave my thumb quite a nip with the pliers. I sucked my thumb until I was seven.