(a.) Producing, or attended with, convulsions or spasms; characterized by convulsions; convulsionary.

baneful black calamitous cataclysmal catastrophic consuming consumptive convulsive deadly demolishing demolitionary depredatory desolating destroying destructive devastating dire disastrous doomful fatal fateful fratricidal grievous herky-jerky insurrectionary internecine jerky nihilist nihilistic orgasmic paroxysmal radical ravaging revolutional revolutionary revulsionary revulsive ruining ruinous seismic self-destructive spasmodic spastic subversionary subversive suicidal sweeping tragic transilient upheaving vandalic vandalish vandalistic wasteful wasting withering wreckful