Merry Jewmas means: This is a unique way to wish someone happy holidays during Hanukkah and Christmas without having to exclude a Christian or Jewish person. An all-inclusive way to send a Christmas greeting to someone who is open to receiving it. Recognizes Christ, as a Jew. However, it also recognizes Jewish people for Hanukkah. This Jewish holiday is observed during the same period that Christmas is in December. (in Community Dictionary, added by Eric Petty)