Here's the problem. In Italian, the signs for the department selling clothing that women wear use the singular while the English uses the plural. This is a phrase rather than two separate words and we think differently about the idea behind it. Try googling "woman's department" in English and it will say, did you mean "women's department?'"
And it is not just the signs in a store. Notice that I didn't write the clothing that a woman wears, although that is grammatically correct--it is just not the normal way of saying it. You can't always translate word for word. DL can be a challenge because sometimes it insists on the literal, but I think they are right here not to accept woman's department.
Well in English the difference is abbigliamento is clothing, while vestiti is dress. English still uses dress to mean both the specific article of clothes as well as the general form for clothes, for instance "that is a beautiful dress" referring to an actual gown, versus "please wear formal dress" that which is required to a ball, wedding, funeral, etc.
I do not know which is more common in Italian usage.
Where is this the case? Woman is singular, that is one female person and women is plural, that is more than one woman. It comes from old English which made plurals very differently from English that has been changed by all the invasions from Europe. So, woman's means something belonging to a single woman and women's means something belonging to several women.
I Googled "abbigliamento donna", making sure to only pay attention to results from Italian websites (with the .it top-level domain) and the results were fairly clear.
abbigliamento donna, some said
abbigliamento da donna, and only a few said
To those insisting that it "should" be one way or the other based on how we say it in English: Never try to apply the rules of one langauage to another. It just doesn't work that way.
"abbigliamento donna" può benissimo significare: "abbigliamento da donna". Il fatto, poi, di tradurre: "L'abbigliamento delle donne" è qualcosa di veramente fantasioso. Si evince, veramente, della creatività da parte dell'autore...Avvisateci prima: "guardate che la traduzione giusta sarebbe "Woman clothing", però non fateci caso perchè questa vuole essere solo una domanda a trabocchetto, così la traduzione vi rimane in mente: è pedagogia...per la formazione del fanciullo...
I got it correct. But, please explain why it is not: Abbigliamento donne - since it is WOMENS - plural clothing
Because phrases are more than the sum of their parts, and different languages put phrases together differently. If you go to a department store in Italy, the signs on the wall and hanging from the ceiling will read "Abbigliamento Donna".
Quoting from higher up on this page:
The issue is not "donna is singular; donne is plural". The issue is how they say it in Italian. And in Italian, they use the singular.
Because that's the idiom in Italian.