ace in the hole

trump card; something that can be saved and used as an advantage later

Ace in the Hole is a slang expression meaning a secret or extra asset to assure success, referring to the ace playing card a player has as a hole card (or face down card) in a game of stud poker.References to this expression include:"Ace in the Hole", a 1909  Tin Pan Alley popular song by James Depsey and George MitchellAce in the Hole (film), a film made in 1951 starring Kirk Douglas"Ace in the Hole (Cole Porter song)", a song by Cole Porter."Ace in the Hole", a 1979 song by Paul Simon."Ace in the Hole", a song by George Strait"Ace in the Hole", song by Bunk Johnson & Lu Watters"Ace in the Hole", song by Dave Van Ronk"Ace in the Hole", song by Jan Menzies"Ace in the Hole", song by Bob Scobey"Ace in the Hole", song by Dukes of DixielandAce in the Hole (book), a science fiction book in the Wild Cards series"That Old Ace in the Hole", title of a novel by Annie Proulx
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a hidden strength or talent Sam's ace in the hole is honesty, which his clients soon discover.

Synonyms and related words:
advantage, backlog, bulge, cache, coign of vantage, drop, edge, flying start, head start, inside track, jump, nest egg, odds, reserve, reserve fund, reserve supply, reserves, reservoir, resource, running start, savings, sinking fund, something extra, something in reserve, start, stockpile, unexpended balance, upper hand, vantage, vantage ground, vantage point, whip hand,
  

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