What does the word shadow mean?

Usage examples for shadow

  1. Like a black shadow, Agnes Barker had passed out of the house. – Mabel's Mistake by Ann S. Stephens
  2. He glanced back just as I opened my eyes, but once more my head was in shadow and the moonlight between us. – The Cavalier by George Washington Cable
  3. But not even the memory of that hour or that youth now threw a shadow upon her heart or life. – Trumps by George William Curtis