The Collaborative International Dictionary of English v.0.48:
Nammu \Nammu\ prop. n. (Sumerian mythology) The Sumerian goddess personifying the primeval sea; mother of the gods and of heaven and earth. [WordNet 1.5]WordNet (r) 3.0 (2006):
Nammu n 1: goddess personifying the primeval sea; mother of the gods and of heaven and earth