any of various low, dense-growing plants, as ivy, pachysandra, etc., used for covering the ground, as in places where it is difficult to grow grass
See ground cover in American Heritage Dictionary 4
Small plants other than saplings, such as mosses, ferns, grasses, and undershrubs, growing on a forest floor; undergrowth.
a. A low-growing dense growth of plants, such as pachysandra or crown vetch, planted for ornamental purposes or to prevent soil erosion in areas where turf is difficult to grow, as in deep shade or on a steep slope.