adj. compelling immediate action; "too pressing to permit of longer delay"; "the urgent words `Hurry! Hurry!'"; "bridges in urgent need of repair"

adj. fraught with extreme danger; nearly hopeless; "a desperate illness"; "on all fronts the Allies were in a desperate situation due to lack of materiel"- G.C.Marshall; "a dire emergency"

adj. of great consequence; "marriage is a serious matter"

adj. intensely or extremely bad or unpleasant in degree or quality; "severe pain"; "a severe case of flu"; "a terrible cough"; "under wicked fire from the enemy's guns"; "a wicked cough"

adj. too closely correlated to be attributed to chance and therefore indicating a systematic relation; "the interaction effect is significant at the .01 level"; "no significant difference was found"

adj. not allowing contradiction or refusal; "spoke in peremptory tones"; "peremptory commands"