weapprev
This command cycles back through your available weapons to the less powerful weapon (however, once you cycle all the way to your least powerful weapon it will then cycle back to your strongest weapon). This command is typically used with a mousewheel. This is commonly used alongside with weapnext.
Ex. If you wanted to set weapprev to cycle downwards through your weapons using the mousewheel you would type the console command bind mwheeldn weapprev. Now when you push your mousewheel backwards you will cycle downward through your weapons.