The thumb is the first digit (finger) of the hand. When a person is standing in the medical Is opposable to the other four fingers; Has two phalanges rather than three; Has greater breadth in the distal phalanx . There is a variation of the human thumb where the angle between the first and second phalanges varies between.
Human thumbs are called opposable thumbs. They are called opposable because the thumb can be moved around to touch the other fingers.
Of all the motions the hand can perform, perhaps none is so distinctively human as a punch in the nose. Other animals bite, claw, butt or stomp.