Millstone

n.

1.

One of two circular stones used for grinding grain or other substance in a mill{1}. No man shall take the nether or the upper millstone to pledge. - Deut. xxiv. 6. Millstone girt (Geol.) a hard and coarse, gritty sandstone, dividing the Carboniferous from the Subcarboniferous strata. See Farewell rock, under Farewell, a., and Chart of Geology. To see into a millstone to see into or through a difficult matter.

Noun	1.	millstone - (figurative) something that hinders or handicaps; "she was an albatross around his neck" Synonyms: albatross
	2.	millstone - any load that is difficult to carry
	3.	millstone - one of a pair of heavy flat disk-shaped stones that are rotated against one another to grind the grain

bale, burdening, burthen, cargo, charge, charging, cheese grater, comminutor, crusher, cumber, cumbrance, deadweight, drag, duty, freight, granulator, grater, grinder, handicap, incubus, incumbency, kominuter, lading, levigator, loading, masher, mill, mortar and pestle, nutmeg grater, onus, oppression, overload, overtaxing, overweighting, pestle, pressure, pulverizer, quern, quernstone, rock crusher, roller, saddling, shredder, steamroller, superincumbency, surcharge, task, tax, taxing, triturator, weight