The Sumerian word NIN (from the Akkadian pronunciation of the sign EREŠ) was used to denote a queen or a priestess, and is often translated as "lady". Other translations include "queen", "mistress", "proprietress", and "lord".
Many goddesses are called NIN, such as DNIN.GAL ("great lady"), DÉ.NIN.GAL ("lady of the great temple"), DEREŠ.KI.GAL, and DWikipedia