Webster's Revised Unabridged Dictionary · 1913

Derby

Derby (?; usually? in Eng.; 85) , noun

1.
A race for three-old horses, run annually at Epsom (near London), for the Derby stakes. It was instituted by the 12th Earl of Derby, in 1780.
Collocations (1)
Derby Day , the day of the annual race for the Derby stakes, -- Wednesday of the week before Whitsuntide.
2.
A stiff felt hat with a dome-shaped crown.