sod

Sod is grass and the layer of soil that's just below it. When you step onto a grassy soccer field, your cleats will sink into the sod.

You can also call sod "turf." A green, grassy lawn is covered with sod, and if you plant a yard with brand new sod, you sod it. Experts know that sod comes either from a Middle Dutch or Middle Low German root, but beyond that it's a bit of a mystery. Some guesses connect it to sog, from the idea of wet sod saturated with water—or soggy sod.