A certain depression and weariness of spirit darken the general tone.
She rested her hands on his arms and they gazed out the window, watching the shadows darken on the farmstead.
Its windows will darken at your command; its air will be automatically purified.
He was performing the same function, but meeting him didn't darken Dean's mood appreciably.
This is one of the chief manufacturing centres in the United Kingdom, and the name arises from the effect of numerous collieries and furnaces, which darken the face of the district, the buildings and the atmosphere.