What does "deathly" mean?

Additional senses

1. 2.Deadly; as, deathly pale or sick. DEATH'S-HEAD Death's"-head`, n. A naked human skull as the emblem of death; the head of the conventional personification of death. I had rather be married to a death's-head with a bone in his mouth. Shak. Death's-head moth (Zoöl.), a very large European moth (Acherontia atropos), so called from a figure resembling a human skull on the back of the thorax; -- called also death's-head sphinx. DEATH'S-HERB Death's"-herb`, n. The deadly nightshade (Atropa belladonna). Dr. Prior.