Definition of Water of Ayr stone in English:

Water of Ayr stone

noun

historical
  • A kind of fine-grained grey stone (either a hardened shale or a claystone) formerly obtained along the banks of the Ayr and used for hones and whetstones and for polishing stone and metal.

Origin

Late 18th century; earliest use found in John Sinclair (1754–1835), agricultural improver, politician, and codifier of ‘useful knowledge’. From Water of Ayr, the name of the Scottish river (now more commonly known simply as the Ayr) at the mouth of which the town of Ayr stands + stone.

Pronunciation

Water of Ayr stone

/ˌwɔːtə(r) əv ˈɛː ˌstəʊn/