Blue Chip
A share in a large, safe, prestigious company, of the highest class among stockmarket investments. A blue-chip company would receive the appellation through being well-known, having a large paid-up capital, a good track record of dividend payments and skilled management.
Be aware this does not mean that all stocks in the FT-SE 100 index are blue chip stocks. Equally it does not mean there are no blue chip stocks outside the FT-SE 100.
The term is American in origin and comes from the card game poker where bluechips were the highest-valued chips in the game - this may be ironic depending on how you view the stockmarket.