The flow, thought to be in the form of convection currents,is powerful enough to fracture the ‘eggshell’ of the crust into plates, and keep them bumping and grinding against each other, or even overlapping, at the rate of a few centimeters a year.
Their grandfather had left his village in order to escape the grinding poverty.
the grinding difficulty of getting to the stadium
I admire their spirit in the face of such grinding tedium.
adj. to come to a grinding halt：突然停下；戛然而止
A car will come to a grinding halt if you put water in the petrol tank.