Roll down and Taper off

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

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

Taper off verb - To grow less in scope or intensity especially gradually.

Roll down and taper off are semantically related. Sometimes you can use "Roll down" instead a verb "Taper off".