solifluction
noun
so·li·fluc·tion ˈsō-lə-ˌflək-shən 
: the slow creeping of saturated fragmental material (such as soil) down a slope that usually occurs in regions of perennial frost
Word History
Etymology
Latin solum soil + -i- + fluction-, fluctio act of flowing, from fluere to flow — more at fluid
First Known Use
1906, in the meaning defined above