Cullen stone (English, noun)
expansion: Cullen stone (countable and uncountable, plural Cullen stones)
Senses:
glosses: A form of black lava quarried in the Rhine Valley and used for millstones.
tags: countable
historical
uncountable
glosses: A millstone made from this substance.
tags: countable
historical
uncountable
Forms:
form: Cullen stones
tags: plural