A large round stone used for grinding grain. / (geology) A coarse-grained sandstone used for making such stones; millstone grit.

plural of millstone.

A nuclear power station near Waterford, Connecticut, USA. / An unincorporated community in Mercer County, New Jersey, United States. / A borough of Somerset County, New Jersey.

burrstone

plural of burr millstone

(archaic, colloquial) To comprehend a difficult matter.

A hard, coarse basaltic millstone from the Rhine region.

plural of lava millstone

Alternative form of see into a millstone

(simile, archaic) Very callous or hardhearted.