I suppose it means that distrust of one kind of assets (Greek government bonds, for example) leads the financial markets to lose confidence in other assets - such as Italian government bonds. In the financial markets it means that the price of the suspected asset drops to reflect the new perceived risk of owning the asset. Completely logical, this.
Since 1998 it has been Standard Operating Procedure that when something went wrong in the world economy, interest rates were lowered and ample liquidity was supplied to the market. Since Asia during the same period took over the production of industrial goods, this policy did not stoke inflation.
The banking crisis in 2008 meant that market participants again are thinking about the correct price of risk. With usual decorum and restraint, the financial markets have entered into a permanent state of catatonic shock.
Now think what could happen if the markets began to ask critical questions about the World’s largest debtor by far, the US of A.