1. 磨砺：修磨石 whetstone | 磨砺 whetting | 钩齿锯 whip saw
1. As he walked down the mountain to leave, he stumbled upon an old woman whetting a metal rod with a stone.
2. To spare no efforts for the education and cultivation of personnel, give attention to whetting their sense of innovation through practice.
3. It accused the United States of " still whetting the sword of aggression " against North Korea under the disguise of seeking peaceful dialogue.