Causing danger; ready to do harm or injury.
The definition of lethal is something very harmful or destructive, especially something that could cause death.
Extreme or terrible:
Capable of injuring or killing by or as by poison; containing, or having the effects of, a poison; toxic; venomous
Find another word for miasmatic. In this page you can discover 7 synonyms, antonyms, idiomatic expressions, and related words for miasmatic, like: miasmal, dangerous, contagious, lethal, deadly, poisonous and miasmic.