| Noun | 1. | millstone - (figurative) something that hinders or handicaps; "she was an albatross around his neck" | |
| 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 graingristmill - a mill for grinding grain (especially the customer's own grain) stone - building material consisting of a piece of rock hewn in a definite shape for a special purpose; "he wanted a special stone to mark the site" | |