Mow a heap, and Mow, to cut down, are quite different words. Mow, a heap, is the Anglo-Saxon mowe,
but mow, to cut down, is the Anglo-Saxon máw-an.

To cut grass is to mow, rhymes with bow and arrrow. When the grass has been cured it is stored
in a part of a barn called a "mow" rhymes with "now".