pins — a number assigned to an individual, used to establish identity in order to gain access to a computer system via an automatic teller machine, a point-of-sale terminal, or other device.
sins — the Akkadian god of the moon: the counterpart of the Sumerian Nanna.
skins — the external covering or integument of an animal body, especially when soft and flexible.
twins — either of two children or animals brought forth at a birth.