From Lifeway Research
Why do English speakers sing “The First Noel,” the French word for Christmas, and not say “The First Weihnachten,” the German word?
By Aaron Earls
Virtually every language has a word for Christmas. Spanish-speakers celebrate Navidad. The Italians have Natale and the Dutch look forward to Kerstmis.
But why do we English speakers sing “The First Noel,” the French word for Christmas, and not say “The First Weihnachten,” the German word?
When was the first noel?
Like many other words in European languages, the French word nöel traces back to Latin and the word natalis, which means “birthday” or “relating to birth.” It’s also the root of English words like neonatal and postnatal.
It’s not difficult to see how the Latin word for birth evolved into a French word celebrating the birth of Christ.
In addition to being the word for Christmas in French, nöel also began to be used to refer to Christmas-related songs, similar to “carols” in English. More Here