Use everyday words.

The “He’s not wearing any apparel!” Test

If they saw a naked man running across a football field, normal people (I think I can speak on behalf of normal people) would say, “He’s not wearing any clothes!” rather than “He’s not wearing any apparel!” There is a time and a place to use non-everyday language like ‘apparel’ but most websites are not those places. Most websites are everyday places and most people visiting these websites are everyday people, so you should stick to using everyday words like ‘clothes’ rather than ‘apparel’. One reason to do this, besides the fact that your users won’t have to do a quick little silent translation (“Apparel—that’s clothes.”), is that when everyday people want to buy clothes, they are going to look for it under ‘clothes’, not ‘apparel’.