Dictionary definition · deadly
adjective
- causing or capable of causing death"a deadly enemy"
- of an instrument of certain death"deadly poisons"
- extremely poisonous or injurious; producing venom"venomous snakes"
- involving loss of divine grace or spiritual death"the seven deadly sins"
- exceedingly harmful
- (of a disease) having a rapid course and violent effect
adverb
- as if dead
- (used as intensives) excessively"she was madly in love"
Source: Open English WordNet (CC BY 4.0).