Synonyms for Dire (same or very similar meaning)
WordNet sense 1 (fraught with extreme danger; nearly hopeless):
desperateWordNet sense 2 (being in or verging on a state of crisis or emergency):
criticalWordNet sense 3 (causing fear or dread or terror):
awful, direful, dread, dreaded, dreadful, fearful, fearsome, frightening, horrendous, horrific, terribleWordNet sense 4 (causing alarm or fear):
alarmingFrom the ODE community, based on WordNetadd/edit