OriginFrom Old Norse suðr, from Proto-Germanic *sunþrą.
Formssuðurs(genitive, singular) · suður(indefinite, nominative, singular) · suðrið(definite, nominative, singular) · suður(accusative, indefinite, singular) · suðrið(accusative, definite, singular) · suðri(dative, indefinite, singular) · suðrinum(dative, definite, singular) · suðurs(genitive, indefinite, singular) · suðursins(definite, genitive, singular)
Source: Wiktionary