Origins: Long has the debate raged over whether a card cheat is properly termed a card sharp or a card shark. Sharks, after all, are known for dispassionately rending the flesh of their prey, which would seem in this linguistic battle to favor the card shark camp, since those who manipulate the pasteboards for the purpose of bilking others have no more conscience or concern for their victims than do their finned counterparts. Yet card sharp also has in its favor that it seems to conjure up mental images of the poker cheats of the Old West, sharp-featured men with cards up their sleeves. Which, therefore, is it?
Both terms still mean someone skilled in cheating at cards, although in recent years card shark has also come to acquire the less odious definition of someone skilled at the play of cards. (Were that not so, one would have to wonder at the naming of the 1978 TV game show Card Sharks, on which contestants tried to guess whether the next card in a sequence was higher or lower than its predecessor.)
As to whether card sharp or card shark entered the English language first, the answer is far from straightforward. A print sighting of card sharp dates to 1884 and one of card sharper to 1859, while the first print sighting of card shark takes us back only to
If you thought the answer might be found via looking at the words sharp and shark absent the word card, that pursuit also leads down a blind alley, because some definitions of both those words contain elements of cheating or connivance.
The Oxford English Dictionary defines a sharp as "A worthless and impecunious person who gains a precarious living by sponging on others, by executing disreputable commissions, cheating at play, and petty swindling; a parasite; a sharper." While that use of the word is rarely encountered these days, remnants of it are still with us, such as when we accuse someone of engaging in "sharp practices" (meaning the cutting of corners to achieve desired ends — while the person so engaged may be staying within the strict letter of the law, his behavior could still be regarded as unethical and suspect).
As for the word shark, in addition to encompassing the species of flesh-eating fish it identifies, it has over time come to serve as a label for certain dislikable characters: those who prey greedily upon others (such as successful businesspeople famous more for their love of profit than for adherence to ethics) and those who by virtue of superior skill outmaneuver less capable opponents (highly effective divorce attorneys, for instance). Common compound nouns have been formed from 'shark' that address both meanings, such as loan shark in the "prey greedily" category and pool shark in the "superior skill" category.
Barbara "all sharks, finned or otherwise, are best avoided" Mikkelson
Last updated: 13 June 2008
The Compact Oxford English Dictionary. Oxford: Clarendon Press, 1993. ISBN 0-19-861258-3.