lasting a very short time; "the ephemeral joys of childhood"; "a passing fancy"; "youth's transient beauty"; "love is transitory but at is eternal"; "fugacious blossoms"
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"