What does the word specter mean?

Usage examples for specter

  1. To me, the specter seems to be receding. – The Captain of the Kansas by Louis Tracy
  2. What had been but blurred under- exposures on the retina of his brain became all at once elfin pictures, weird and specter- like as the dissolving views of a camera obscura. – The Valiants of Virginia by Hallie Erminie Rives