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ach-y-fi

British  
/ ˌaxəˈviː, ˌʌx- /

interjection

  1. dialect  an expression of disgust or abhorrence

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of ach-y-fi

Welsh, probably from ach, achy general exclamation of disgust + fi I, me