https://en.wikipedia.org/wiki/Diminutive
> A diminutive is a word obtained by modifying a root word to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment, and sometimes to belittle something or someone.
Yeah, it's funny, a word consisting both of an augmentative (the opposite of diminutive) and a diminutive.
Were you thinking of „Verkleinerungsform“? Do people still use those Germanized terms? It feels a little old-fashioned to me, like saying „besitzanzeigendes Fürwort“ instead of Possessivpronomen.
In a way? I always found it more sensible to use German words like "Namenwort" instead of "Nomen" to express German grammar, instead of using latin terms. After all Latin is a language that comes from a completely different language family to start with and is not used at all in Germany except when wanting to pretend you're fancy (law, medicine, grammar).
I now accept that I am losing my French while not being really fluent in any other language.