From Longman Dictionary of Contemporary Englishseal somebody’s fateseal somebody’s fateCERTAINLY/DEFINITELYto make something, especially something bad, sure to happen The outbreak of war sealed the government’s fate. → seal
                                                    
                                                Examples from the Corpus
seal somebody’s fate• Rogerson's fate was sealed when he got behind the wheel of his car, completely drunk. 
