deathly

adjective

1. causing death; deadly; fatal.
2. like death: a deathly silence.
3. of, relating to, or indicating death; morbid: a deathly odor from the sepulcher.

adverb

4. in the manner of death.
5. very; utterly: deathly afraid.

adjective

1. deadly
2. resembling deatha deathly quiet

adj.

Old English deaþlic “mortal” (see death). Meaning “deadly” is from late 12c.; that of “death-like” is from 1560s.