I always loved the term "cargo pants". I mean, I'm sure these were invented for some specific trade, and have now been turned in to a fashion by some mindless twit. To me, cargo implies your regular pants aren't working hard enough! They need some extra pockets and such to seem worthy, while your other pants might be saying "enough, already! We work hard enough to hold up your fleshy bottom! Give us some more pockets!"
I just purchased a pair of "cargo" type pants from a yoga type online store. Now, my neighbor Amy has these same pants, I believe, but on her they're more like "oh your cute and perky bottom is so adorable and we're so honored to be carrying you, we'll just put some lip gloss in this little side pocket, the better to show off your adorableness." MY cargo pants, on the other hand, are about five sizes bigger (and, ok, shorter, which is why I got them in the first place -they are not jeans and they are short enough to fit me). My cargo pants are saying, "yes, finally, you twit! You get it. You need to carry a thigh in each of these pockets in order to fit your ample behind in here!" I'm not sure I'll be cute and adorable in these pants. But I'm sure they have enough spaces in which to hold my various parts. For sure they earn their name. Cargo indeed!