The word Christmas originated as a contraction of "Christ's mass". It is derived from the Middle English Christemasse and Old English Cristes mæsse, a phrase first recorded in 1038, compounded from Old English derivatives of the Greek christos and the Latin missa.In early Greek versions of the New Testament, the letter Χ (chi), is the first letter of Christ. Since the mid-16th century Χ, or the similar Roman letter X, was used as an abbreviation for Christ.^[2] Hence, Xmas is often used as an abbreviation for Christmas.  

How "Merry Christmas" is said .....

Afrikaans: Geseënde Kersfees
African/ Eritrean/ Tigrinja: Rehus-Beal-Ledeats
Arabic: Milad Majid
Argentine: Feliz Navidad
Brazilian: Feliz Natal
Bulgarian: Tchestita Koleda; Tchestito Rojdestvo Hristovo
Catalan: Bon Nadal i un Bon Any Nou!
Chile: Feliz Navidad
Chinese: (Cantonese) Gun Tso Sun Tan'Gung Haw Sun
Chinese: (Mandarin) Kung His Hsin Nien bing Chu Shen Tan (Catonese) Gun Tso Sun Tan'Gung Haw Sun
Columbia: Feliz Navidad y Próspero Año Nuevo
Croatian: Sretan Bozic
Danish: Glædelig Jul
Dutch: Vrolijk Kerstfeest en een Gelukkig Nieuwjaar! or Zalig Kerstfeast
English: Merry Christmas
Esperanto: Gajan Kristnaskon
Estonian: Ruumsaid juulup|hi
Ethiopian: (Amharic) Melkin Yelidet Beaal
French: Joyeux Noel
Frisian: Noflike Krystdagen en in protte Lok en Seine yn it Nije Jier!
Galician: Bo Nada
Gaelic: Nollaig chridheil agus Bliadhna mhath ùr!
German: Fröhliche Weihnachten
Greek: Kala Christouyenna!
Hawaiian: Mele Kalikimaka
Hebrew: Mo'adim Lesimkha. Chena tova
Hindi: Shub Naya Baras
Hausa: Barka da Kirsimatikuma Barka da Sabuwar Shekara!
Icelandic: Gledileg Jol
Indonesian: Selamat Hari Natal
Iraqi: Idah Saidan Wa Sanah Jadidah
Irish: Nollaig Shona Dhuit, or Nodlaig mhaith chugnat
Italian: Buone Feste Natalizie
Japanese: Shinnen omedeto. Kurisumasu Omedeto
Jiberish: Mithag Crithagsigathmithags
Korean: Sung Tan Chuk Ha
Lao: souksan van Christmas
Latin: Natale hilare et Annum Faustum!
Occitan: Pulit nadal e bona annado
Papiamento: Bon Pasco
Papua New Guinea: Bikpela hamamas blong dispela Krismas na Nupela yia i go long yu
Pennsylvania German: En frehlicher Grischtdaag un en hallich Nei Yaahr!
Peru: Feliz Navidad y un Venturoso Año Nuevo
Philipines: Maligayan Pasko!
Polish: Wesolych Swiat Bozego Narodzenia or Boze Narodzenie
Portuguese:Feliz Natal
Pushto: Christmas Aao Ne-way Kaal Mo Mobarak Sha
Rumanian: Sarbatori vesele or Craciun fericit
Russian: Pozdrevlyayu s prazdnikom Rozhdestva is Novim Godom
Serbian: Hristos se rodi
Slovakian: Sretan Bozic or Vesele vianoce
Sami: Buorrit Juovllat
Samoan: La Maunia Le Kilisimasi Ma Le Tausaga Fou
Serbian: Hristos se rodi.
Slovak: Vesele Vianoce. A stastlivy Novy Rok
Slovene: Vesele Bozicne Praznike Srecno Novo Leto or Vesel Bozic in srecno Novo leto
Spanish: Feliz Navidad
Swedish: God Jul and (Och) Ett Gott Nytt År
Turkish: Noeliniz Ve Yeni Yiliniz Kutlu Olsun
Ukrainian: Srozhdestvom Kristovym or Z RIZDVOM HRYSTOVYM
Urdu: Naya Saal Mubarak Ho
Vietnamese: Chuc Mung Giang Sinh