The origins of words often intrigue, particularly in the way we have frequently changed the original and fundamental meaning of a word (as in our use of the of the word "awesome" today). Because I do not spend a great deal of time studying the origins of words, sometimes an awareness of an original meaning simply hits me, as it were, out of the blue (usually when I'm walking along thinking about other things without paper to write on).
Today, though, as I went on my daily walk through the streets of Rome listening to podcasts of Catholic Answers Live (this time to stock up on Dr Pepper before five forecasted days of rain arrive over Rome), I listened to Steve Ray (with whom you really should go on pilgrimage) explain the original meaning of the word denomination.
The word first made its way into the English language in the late 1300s, coming from a French word (the Norman conquest of 1066 began a long history of the incorporation of French words into the English language, like pork and beef) of Latin origins.
The English word "denomination" comes from the French word "denominacion," meaning, "nominating" or "naming." The French word "denominacion" comes from the Latin word denominationem, meaning, "a calling by anything other than the proper name." The Latin word denominationem has its origins in another Latin word, denominare, meaning, "to name."
In the 1650s the word denomination was applied to currency and in 1716 it was given an additional, new meaning: "a religious sect."
Why did these "religious sects" have to be called by anything other than the proper name? This chart answers the question rather well:
Calling them denominations disguises the historical fact that none of the various Protestant denominations are what Jesus established when he said to Simon Peter, "And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it" (Matthew 16:18), or when he instructed his disciples, "If he will not listen to them, tell the church" (Matthew 18:17).
Notice that the word church is singular in both instances; Jesus establish one church, not several. And if none of the Protestant denominations have a historical beginning prior to the 1500s, they simply cannot be the church to which Jesus referred.