Quiz: Remember the definition of mal de mer?
late 14c., a Bible word, from Greek maranatha, untranslated Semitic word in I Cor. xvi:22, where it follows Greek anathema, and therefore has been taken as part of a phrase and used as "a curse." Usually assumed to be from Aramaic maran atha "Our Lord has come," which would make the common usage erroneous (see OED entry), but possibly it is a false transliteration of Hebrew mohoram atta "you are put under the ban," which would make more sense in the context. [Klein]
(1 Cor. 16:22) consists of two Aramean words, Maran'athah, meaning, "our Lord comes," or is "coming." If the latter interpretation is adopted, the meaning of the phrase is, "Our Lord is coming, and he will judge those who have set him at nought." (Comp. Phil. 4:5; James 5:8, 9.)