Source : WordNet®

life-threatening
     adj : 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" [syn: {dangerous}, {grave},
            {grievous}, {serious}, {severe}]