leaden

Made of lead.

Pertaining to or resembling lead; grey, heavy, sluggish.

Where but to think is to be full of sorrow / And leaden-eyed despairs, / Where Beauty cannot keep her lustrous eyes, / Or new Love pine at them beyond to-morrow.

Which break a teachless nature to the yoke.

Dull; darkened with overcast.

the sky was leaden and thick

It was at the end of February..., when the world was cold..., when icy rains fell from the leaden skies in continual drizzling showers.

To make or become dull or overcast.