bluestone

/ˈbluːˌstoʊn/
noun
  1. A bluish-gray building stone, especially a type of sandstone or limestone used in construction and paving.
    • The old church was built with local bluestone quarried from the nearby hills.
    • They laid a bluestone patio in the backyard for summer barbecues.
    • The city's historic sidewalks are made of worn bluestone slabs.
  2. A copper sulfate compound used as an agricultural fungicide or algicide.
    • Farmers sometimes use bluestone to control fungus on their grapevines.
    • The pond was treated with bluestone to kill the algae bloom.
    • Gardeners apply bluestone sparingly to prevent blight on tomato plants.
What does "bluestone" mean? | whatsthatwordmean | whatsthatwordmean