whinstone Meaning, Definition & Usage

  1. noun any of various hard colored rocks (especially rocks consisting of chert or basalt)
    whin.

WordNet

Whin"stone" noun
Etymology
Whin + stone; cf. Scot. quhynstane.
Definitions
  1. A provincial name given in England to basaltic rocks, and applied by miners to other kind of dark-colored unstratified rocks which resist the point of the pick. -- for example, to masses of chert. Whin-dikes, and whin-sills, are names sometimes given to veins or beds of basalt.

Webster 1913