life-threatening Synonyms

severe serious grave grievous dangerous perilous pernicious peracute poisonous parlous precarious risky noxious very bad terrible severer unsafe death-dealing deadliest autoimmune unhealthy vulnerable virulent toxic threatening threatened mortal menacing malignant detrimental destructive desperate deleterious deathly deadly critical catastrophic capital awful dire dreadful lethal insecure injurious hazardous harmful graver fatal existential endanger