o·ver·cast • adj. / ˈōvərˌkast; ˌōvərˈkast/ 1. (of the sky or weather) marked by a covering of gray clouds; dull: a chilly overcast day.2. (in sewing) edged with stitching to prevent fraying.• n. / ˈōvərˌkast/ clouds covering a large part of the sky: the sky was leaden with overcast.• v. / ˌōvərˈkast/ (past and past part. -cast) [tr.] 1. cover with clouds or shade: the pebbled beach, overcast with the shadows of the high cliffs.2. stitch over (an unfinished edge) to prevent fraying.