Deathly
Part of speech: adjective
Definition: Appearing as though dead, or on the verge of death. Causing death.
Part of speech: adverb
Definition: With reference to death extremely, dreadfully
Mortal
Part of speech: adjective
Definition: Susceptible to death by aging, sickness, injury, or wound
Part of speech: noun
Definition: A human; someone susceptible to death.
Example sentence: To live in this world, you must be able to do three things: to love what is mortal; to hold it against your bones knowing your own life depends on it; and, when the time comes to let it go, to let it go.