|1.||horse chestnut water chestnut Compare dwarf chestnut any N temperate fagaceous tree of the genus Castanea, such as C. sativa (sweet or Spanish chestnut), which produce flowers in long catkins and nuts in a prickly bur|
|2.||the edible nut of any of these trees|
|3.||the hard wood of any of these trees, used in making furniture, etc|
|4.||a. a reddish-brown to brown colour|
|b. (as adjective): chestnut hair|
|5.||a horse of a yellow-brown or golden-brown colour|
|6.||a small horny callus on the inner surface of a horse's leg|
|7.||informal an old or stale joke|
|[C16: from earlier chesten nut: chesten, from Old French chastaigne, from Latin castanea, from Greek kastanea]|
"When suddenly from the thick boughs of a cork-tree --"
"A chestnut, Captain; a chestnut."
"Bah! booby, I say a cork-tree!"
"A chestnut," reiterates Pablo. "I should know as well as you, having heard you tell the tale these twenty-seven times."
see old chestnut.