Part of speech: Noun
the quality of being deadly
Categories: Unwholesomeness, Morbidness, Morbidity
Lethality, Deadliness
The word "deadliness" comes from Old English dēadlīcnes, which comes from Middle English dedlinesse.
deadly – A related word in the same word family.
ness – A related word in the same word family.
Old English had grammatical genders for nouns, like German does today.