The Oxford Thesaurus An A-Z Dictionary of Synonyms - fatal adj.

1) fateful, deadly, murderous, lethal, mortal, toxic, terminal, final; baneful, poisonous: She drank the fatal potion without a word. Who dealt the fatal blow? 2 destructive, fateful, ruinous, calamitous, dreadful, disastrous, devastating, cataclysmic, catastrophic, harmful, mischievous, damaging: Discovery by the police would prove fatal to our plan. 3) fateful, fated, destined, predestined, decreed, ordained, foreordained, preordained, predetermined, inevitable, unavoidable, necessary, essential, inescapable, ineluctable: The events fell into their fatal sequence.