Roll down and Roll up

Roll down verb - Gather into a huge mass and roll down a mountain, of snow.

Roll up and roll down are semantically related. In some cases you can use "Roll up" instead a verb "Roll down".

Roll up verb - To become greater in size, extent, volume, amount, or number.

Roll down and roll up are semantically related. Sometimes you can use "Roll down" instead a verb "Roll up".