The Collaborative International Dictionary of English v.0.48:

Greensward \Green"sward`\ (-sw[add]rd') n.
   Turf green with grass.
   [1913 Webster]

WordNet (r) 3.0 (2006):

greensward
    n 1: surface layer of ground containing a mat of grass and grass
         roots [syn: turf, sod, sward, greensward]