millstone

/ˈmɪlˌstoʊn/
noun
  1. One of a pair of large, flat, circular stones used for grinding grain in a mill.
    • The grooves on the millstone helped crush the wheat efficiently.
    • The miller replaced the worn millstone with a new one from the quarry.
    • Grain was fed between the two millstones to make flour.
  2. A heavy burden or responsibility that is difficult to bear.
    • She felt the millstone of caring for her aging parents alone.
    • The failed project was a millstone that dragged down the whole company.
    • The debt became a millstone around his neck.
Synonyms
What does "millstone" mean? | whatsthatwordmean | whatsthatwordmean