Base/root of increment and decrement

I'm tasked with a morphological analysis of incrementing. I would say that crement is the base of increment and the root of the word. But I'm curious, because all my life I've been thinking about the words increment and decrement differently.¹

Would the morpheme crement be referred to as a "cranberry morpheme" and if so, did it once mean something on its own in English? I've looked up some etymology, and understand the Latin origin of the words—incrementum and decrementum.

• Did the words come entirely as units from Latin? Or did we get the two morphemes in each individually and combine them?
• If they did come as units from Latin, can we still consider crement a cranberry morpheme, given that it did not ever exist on its own in English? Does it even make sense, then, to break it up into in + crement or is the word atomic? Can we consider, in morphological analysis, previous versions of words if they are in other languages?

^{1 For some reason, I've always thought of increment and decrement in the same way as I've thought of accelerate and decelerate (accelerate being a word on its own and decelerate being contrived to take away from accelerate and "opposite" it). I suppose I was entirely wrong, as both incrementum and decrementum existed in Latin, and crementum indeed means something.}

Solution 1:

Well described question.

I wonder if it would clarify some of your thoughts it you replaced "increment and decrement" with "increase and decrease" and then run through the same questions. (Tim posted his similar thought while I was writing this).

We don't say that the root word there is 'crease'. What we observe is a side effect of a particular form/tense of a word that also has a prefix. Or we could say it's a word that atomized in English after a root had been both prefixed and suffixed, which obscures the form.

As you observe this is similar to what's happening with accelerate and decelerate.

Here is etymology for crew, which demonstrates some interesting relationships.

So as you examine "increment and decrement" keep in mind that the root (albeit obscured) is the same as increase, accrue, crescendo, recruit, and create.

Solution 2:

Per the MED, we have during the Middle English period the nouns en|increment (L. incrementum) and incrementacioun (ML incrementatio) and the verb in|encresen (AF encreiss-, encress-, CF encroiss-; L incrēscere.).

Many modern speakers when seeing increase and decrease would know that -crease is probably meaningful and related to crescent and crescendo. Whether they would make the morphological leap from -crease to -crement is doubtful, though Chaucer might have done so. Many modern speakers would have no idea that crescent has anything to do with increase.

You could probably survey a few hundred randomly chosen speakers and ask them what the opposite of "increment" is, and get close to an answer.