The definition of deathly is something that is related to or likely to cause death.
A person who is extremely ill and likely to die is an example of someone who would be described as deathly ill.
- Archaic causing death; deadly
- like or characteristic of death
Origin of deathlyMiddle English dethlich from Old English d?athlic: see death
- in a deathlike way; to a deadly degree
- extremely: deathly ill
- Of, resembling, or characteristic of death: a deathly silence.
- Causing death; fatal.
- In the manner of death.
- Extremely; very: The night was deathly cold.
(comparative deathlier or more deathly, superlative deathliest or most deathly)