\Re"gent di"a*mond\
A famous diamond of fine quality, which weighs about 137
carats and is among the state jewels of France. It is so
called from the Duke of Orleans, Regent of France, to whom it
was sold in 1717 by Pitt the English Governor of Madras
(whence also called the {Pitt diamond}), who bought it of an
Indian merchant in 1701.