The Collaborative International Dictionary of English v.0.48:
Nerthus \Nerthus\ prop. n. The Teutonic goddess of fertility; later identified with Norse Njord. Syn: Hertha. [WordNet 1.5]WordNet (r) 3.0 (2006):
Nerthus n 1: the Teutonic goddess of fertility; later identified with Norse Njord [syn: Nerthus, Hertha]