Definify.com

Webster 1913 Edition

Adj.

Deadly; fatal; mortal; destructive.

adv.

Deadly;

as,

deathly

pale or sick

deathly ‎(comparative deathlier or more deathly, superlative deathliest or most deathly)

Appearing as though dead, or on the verge of death.
He has a deathly pallor.
Fatal, causing death.
Extreme.
He has a deathly fear of crocodiles.

appearing as though dead

fatal, causing death

Russian: смерте́льный (ru) ‎(smertélʹnyj), роково́й (ru) ‎(rokovój), фата́льный (ru) ‎(fatálʹnyj)

extreme

deathly ‎(comparative more deathly, superlative most deathly)

In a way that resembles death.
He was deathly pale.
Extremely, dreadfully.

The water was deathly cold.

He was deathly afraid of crocodiles.