The Sumerian word NIN (𒎏), later borrowed into Akkadian, was used to denote a queen or a priestess, and is often translated as "lady". Other translations include "queen", "mistress", "proprietress", and "lord".^[1] The word EREŠ, also meaning "queen" or "lady",^[2] is written using the cuneiform sign for NIN as well.

Many goddesses are called NIN or EREŠ, such as ^DNIN.GAL ("great lady"), ^DÉ.NIN.GAL ("lady of the great temple"), ^DEREŠ.KI.GAL, and ^DNIN.TI.

The compound form NIN.DINGIR ("divine lady" or "lady [of a] god"), denotes a priestess.

In writing

NIN originated as a ligature of the cuneiform glyphs of MUNUS (𒊩) and TÚG (𒌆); the NIN sign was written as MUNUS.TÚG (𒊩𒌆) in archaic cuneiform, notably in the Codex Hammurabi.^{[citation needed]} The syllable nin, on the other hand, was written as MUNUS.KA (𒊩𒅗) in Assyrian cuneiform. MUNUS.KU = NIN₉^{[clarification needed]} (𒊩𒆪) means "sister".^{[citation needed]}

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  Basic cuneiform MUNUS sign ("woman")
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  Basic cuneiform TÚG sign (syllable ku)

Occurrence in the Gilgamesh epic

Ninsun (^DNIN.SÚN) as the mother of Gilgamesh in the Epic of Gilgamesh (standard Babylonian version), appears in 5 of the 12 chapters (tablets I, II, III, IV, and XII). The other personage using NIN is the god Ninurta (^DNIN.URTA), who appears in Tablet I, and especially in the flood myth of Tablet XI.^{[citation needed]}

Of the 51 uses of NIN, the other major usage is for the Akkadian word eninna (nin as in e-nin-na, but also other variants). Eninna is the adverb "now", but it can also be used as a conjunction, or as a segue-form (a transition form).^{[citation needed][clarification needed]}

The two uses of NIN as the word for "sister" (Akkadian ahātu), for example, are used in Tablet 8 (The Mourning of Enkidu), line 38:^{[citation needed]}

"May…

"May the brothers go into mourning over you like sisters…"