n
1 either of a pair of flat circular stones between which grain is ground 磨石; 磨盘.
2 (idm 习语) a millstone round one's/sb's `neck heavy burden or responsibility 沉重的负担或责任
*My debts were like a millstone round my neck. 我欠的债像是在脖子上套着个磨盘.

n[C]
one of the two large circular stones that crush grain into flour in a mill
a millstone round/around sb's neck
something that causes a lot of problems for someone, and that they cannot get rid of
　Inflation is still a millstone round the neck of British businesses.