The little finger.
- She chewed grimly on the fingernail of her little pinkie, narrowing her eyebrows in frustration.
- On a normal keyboard, the resting position for my left hand has my pinkie and ring finger touching the side of the keyboard.
- The nails on her pinkie and index finger were crushed.
Entry from British & World English dictionary
noun (plural pinkies)informal
late 19th century: from pink2, of obscure origin.