An innate or learned ability to detect and prevent an unfortunate situation, generally of a financial nature and in a dealing with a Jew, where one would be subjected to a bad deal, agreement, theft, or other form of loss.
Can you believe that kike was trying to pass that Rollex clone off as the real thing?  He was even asking $1,000 for it.  It is a good thing that my jewdar was working.
by Alpha Aquarius January 18, 2009
 Get the jewdarmug.
Get the jewdarmug. An ability to find the best bargains anywhere in the shopping vicinity.  Based on the stereotypical, yet often held true by Jews, belief that Jews are cheap.
by jewcygirl April 18, 2006
 Get the jewdarmug.
Get the jewdarmug. a nonexistent ability that people claim to have. such people believe they can "sense" a Jew. obviously this is impossible unless the Jew has the distinctive hairstyle of the Orthodox sect or is wearing a yarmulke, since Jews aren't another race and look just like everyone else.
some guy: according to my jewdar, you're Jewish.
me: yeah, and the fact that I'm wearing a star of david had nothing to do with it. shmuck.
me: yeah, and the fact that I'm wearing a star of david had nothing to do with it. shmuck.
by Shwaggy January 15, 2004
 Get the jewdarmug.
Get the jewdarmug.