Definition of "garn"

garn¹

noun
uncountable
1. (obsolete) yarn (twisted fibers for weaving)

garn²

interjection
1. (Cockney slang) A response that expresses disbelief or mockery.
  Quotations
  Mrs Pearce: […] She may be married.Liza: Garn!
  1912, George Bernard Shaw, “Act II”, in Pygmalion‎