A pair of cargo pants.
The definition of cargo pants are a style of casual trousers that have multiple large pockets, some of which are typically on the side of the upper leg.
An example of cargo pants are slacks worn by a man who carries water, keys, a drink and an iPod in multiple different pockets.
loosefitting, casual pants having a number of cargo pockets, some typically on the side of the upper leg
Loose-fitting, usually cotton pants having cargo pockets partway down the sides.