Sometimes when a word is borrowed from one language to another, what is an inflected form in the source language becomes an uninflected form in the target language. Examples of this are the Italian words "salame", "panino", and "zucchino", whose plural forms "salami", "panini", and "zucchini" got borrowed into English as unmarked singular forms.
Is there a term for this kind of borrowing? I'm tempted to call it a "reanalytic borrowing" but that term doesn't appear to be in general use, and besides which probably covers a greater range of phenomena than what I've described above.