A stock is considered highly liquid (or simply liquid) if it is widely available and people are willing to buy and sell it. Stocks with limited public shares, or ones that are over or under valued will be hard to move, becoming illiquid. The same terms can be applied to almost any item, from commodities like oil, to currencies like the US Dollar, to trinkets like Beanie Babies[?].
wikipedia.org dumped 2003-03-17 with terodump