whopper

Etymology

whop + -er

noun

1. (informal) Something remarkably large.
   There's a storm blowing up, Sylvester—a 'whopper', speaking in the vernacular of the peasantry. 1939, Noel Langley, Florence Ryerson, Edgar Allan Woolf, The Wizard of Oz
2. (informal) An outrageous or blatant lie.
   Isuzu Inc. hit pay dirt in the late '80s with its series of “Joe Isuzu” spots, featuring an oily, Satanic-looking salesman who told whoppers about Isuzu's genuine llama-skin upholstery and ability to run on tapwater. 1997 [1990], David Foster Wallace, “E Unibus Pluram: Television and U.S. Fiction”, in A Supposedly Fun Thing I’ll Never Do Again: Essays and Arguments, Boston, Mass.: Little, Brown and Company