blow off course

Verb

blow off course (third-person singular simple present blows off course, present participle blowing off course, simple past blew off course, past participle blown off course)

1. (figuratively, transitive, often in the passive) To affect negatively, often in an unexpected manner; to derail.
   • He deserves every credit for establishing Labour as the party of economic competence, for reversing a generation of neglect in the public services and for achieving more than any previous Prime Minister in promoting Britain's place in Europe, until the hurricane over his support for the war on Iraq...2003, Robin Cook, “Prologue”, in The Point of Departure: Why One of Britain's Leading Politicians Resigned over Tony Blair's Decision to Go to War in Iraq, London: Simon & Schuster UK, →ISBN, page 1
   • As a man proud to shape his own destiny, he found it shameful when events blew him off course. It didn't take tragedy or war to derail a man. It took only a memory.2009, Ali Shaw, The Girl With Glass Feet, London: Atlantic Books, →ISBN, page 38