Definition of rockstone in US English:

rockstone

(also racca tone, rack tone, rokka-tone)

noun

Caribbean
  • 1Rock, especially when used as a coarse building stone.

  • 2A stone; (in later use) especially a small stone, a pebble.

Origin

Mid 16th century; earliest use found in John Bale (1495–1563), bishop of Ossory, evangelical polemicist, and historian. From rock + stone.

Pronunciation

rockstone

/ˈrɒkstəʊn/