Moin

A Northern German and (East) Frisian greeting used all day long, not only in the morning, and often doubled as 'Moin moin'. Its origin is not entirely certain: a widespread derivation is from Frisian/Low German 'moi/mooi' (nice, good), i.e. 'a good (day)'; another reading takes it as a shortening of 'guten Morgen' (good morning). Wiktionary even considers different regional etymologies possible.