Cargo pants are
pants designed much like
khakis only with a large
utility pocket (roughly the size of a
CD jewel case) on the outside of each leg at about
knee height.
In my experience, they come in three flavors:
loose - something like a comfortable pair of slacks
baggy - for those who find don't like the feel of wearing pants but like wearing them
far too big - who invented these?
The utility pockets tend to come in really handy if you're a geek with a lot of toys. Things I sometimes carry in the pockets of my cargo pants in order of frequency (highest first):
I've also heard them referred to as
pants of holding (+1).