Definition of saddle rock in English:

saddle rock

noun

US
historical
  • (In full "saddle rock oyster") a very large edible oyster.

Origin

Mid 19th century; earliest use found in Lantern (New York). From Saddle Rock, the name of a saddle-shaped boulder off the north coast of Long Island, New York, below which a bed of large oysters was found in 1827.