grindstone['ɡraindstəun]n.1.■(用于研磨、研削等用的)砂石;磨石2.■石磨get back to the grindstone重新干枯燥乏味的工作;回到(枯燥艰苦的)工作岗位keep (或have,put)one's nose to the grindstone埋头苦干