adjective
deadlier; -est
[or more ~; most ~]
causing or able to cause death
extremely accurate and effective
always used before a noun :extreme or complete
informal :very boring
synonyms deadly, mortal, fatal, and lethal mean causing or able to cause death. deadly describes something that is very dangerous and likely or able to cause death.
adverb
deadlier; -est
[or more ~; most ~] :extremely or completely