causing fear or anxiety by threatening great harm; "a dangerous operation"; "a grave situation"; "a grave illness"; "grievous bodily harm"; "a serious wound"; "a serious turn of events"; "a severe case of pneumonia"; "a life-threatening disease"
involving or causing danger or risk; liable to hurt or harm; "a dangerous criminal"; "a dangerous bridge"; "unemployment reached dangerous proportions"
syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions); low doses cause diarrhea and nausea and vomiting and sometimes loss of hair; greater exposure can cause sterility and cataracts and some forms of cancer and other diseases; severe exposure can cause death within hours; "he was suffering from radiation"
a toxic condition caused by ingesting or inhaling mercury; acute mercury poisoning causes a metallic taste and vomiting and diarrhea and kidney problems that may lead to death