Today, Merriam-Webster's word of the day deserves some kind of award. I have literally never before heard or read the word "syncategorematic" in any context. My spell-checker thinks it doesn't exist.

Since the definition is a little dense, I'll expound a tad -- it means words that are meaningful only along with other words, such as "all" and "any" and "the". It comes from a reference to the modifier words in old Greek logical propositions like "all men are mortal, Socrates is a man, therefore Socrates is mortal". The nouns and adjectives (men, Socrates, mortal) were kategorema, or categorem, so the words that accompanied them were syncategoremata, or roughly "things that show up with the kategorema".