Origin: Germanic Old English prefix
Overcast has 11 different meanings across 3 categories:
the state of the sky when it is covered by clouds
"The sudden shift from sunshine to overcast skies made me rethink my plans for a picnic."
gloomy semidarkness caused by cloud cover
"The sky turned a heavy, gray overcast that made me hesitate before stepping out without an umbrella."
a long whipstitch or overhand stitch overlying an edge to prevent raveling
"The tailor secured the hem of the skirt by running an overcast stitch along the raw edge."
a cast that falls beyond the intended spot
"The ball sailed high and overcast, landing far past where the batter had aimed it."
An outcast.
"The overcast was always left to clean up the messes while everyone else enjoyed the party."
sew over the edge of with long slanting wide stitches
"She used a thick yarn to overcast the raw edges of her sweater so they wouldn't unravel during washing."
To overthrow.
"The rebellion overcast the corrupt regime within hours."
filled or abounding with clouds
"The sky was completely overcast, hiding even the faintest hint of blue behind a thick layer of gray clouds."
Covered with clouds; overshadowed; darkened; (meteorology) more than 90% covered by clouds.
"The sky remained overcast all morning, keeping the temperature cool and blocking out any hint of sunlight."
Overcast comes from Middle English, formed by combining the prefix over- with the word cast. Originally, it meant to throw or spread something over a surface.