A friend of mine asked me recently as to the origins of the Japanese name for the voluminous giver of gifts, Santa Claus.

A direct transcription of the name Santa Claus is サンタクロース (Santa Kurôsu), but he is typically referred to as サンタさん (Santa-san), literally something to the effect of "Mr. Claus," but -san itself hasn't the strictness that "mister" has in English and as such merely implies a level of familiarity or politeness.

The name of the saint, whose name inspired Santa Claus, Saint Nicholas of Myra, is rendered as 聖ニコラス (Sei Nikorasu), where 聖 (sei) literally means "holy" or "sacred", but as a borrowed over usage from Church Latin is used as a suffix for saintly names.

Wikipedia refers to him as ミラの聖ニコラオ (Mira no Sei Nikorasu, "Saint Nicholas of Myra), thus including the toponym joined with the genitive suffix の (no), that can work as a "of" as in English.

On a related note 聖 can also archaically be read as hijiri, referring to virtuous monks in the past, where the name literally means "the one who knows the days (upon which to divine)", stemming in all likelihood from the even more archaic 日知り (hishiri, "day-knowing").

The UK version of the gift-giver, Father Christmas is also rendered in katakana as ファーザー・クリスマス (Fâzâ Kurisumasu), though it is quite obscure compared to the name of his American colleague, Santa Claus - I could only really find articles referencing to how Australia celebrates Christmas as well as a very passing mention of the name, but not directly in Wikipedia's Japanese entry on the character, it itself merely being a re-direct.

In the film Arthur Christmas, the 136 year old grandfather voiced by Bill Nighy, is affectionately called "Grandsanta" by those around him, which is translated in the subtitles as おじサンタ (Ojisanta, "Grampa Santa") and in the dub itself merely as おじいちゃん (ojiichan, "gramps/grandad"), thus foregoing the nickname entirely, for the regular informal word for one's own grandfather.