Sentence:  [http://www.newstatesman.com/life-and-society/2007/12/birthday-jesus-lady-god Richard Dawkins mentioned] the idea of calling it <WSD>Newtonmas</WSD>, because Isaac Newton was also born–I say also, I mean Newton "actually was"–born on the 25th of December. 
Meaning of the word marked with <WSD> tags:  December 25, Sir Isaac Newton's birthday (in the Julian calendar).