WordNet sense 1 (the state of the sky when it is covered by clouds):

cloudiness, cloud cover

WordNet sense 2 (a long whip stitch or overhand stitch overlying an edge to prevent raveling):

overcasting

WordNet sense 3 (make overcast or cloudy):

cloud

WordNet sense 4 (filled or abounding with clouds):

sunless, cloud-covered, clouded

WordNet sense 5 (full of or covered with clouds):

cloudy