What do bullish and bearish markets mean?

When the markets are up we call them 'bull' markets and when the markets are down we call them 'bear' markets. At a point in time, we do not know whether market is in a bull mode or in a bear mode. Only at a later date we are able to see a bull run or a bear run - in retrospect. So now we know that 2003 to 2007 was a bull market, 2008 was a bear market, ...whether 2014 was a bull market or was it a bear market will be known sometime in 2016!