n. (指人)指关节(指动物)膝关节, 踝[/scode]
Your knuckles are the rounded pieces of bone that form lumps on your hands where your fingers join your hands, and where your fingers bend.
①The girl tapped the door with her knuckles.
②Our fingers bend at the knuckle.
③Like you'd get your knuckles bloody for me.
If someone knuckles down, they begin to work or study very hard, especially after a period when they have done very little work.
①The only thing to do was knuckle down and get on with some serious hard work.
②He managed to knuckle down to his lessons long enough to pass his examination.
If you knuckle under, you do what someone else tells you to do or what a situation forces you to do, because you realize that you have no choice.
①It is arguable whether the rebels will knuckle under.
②The United States, he said, did not knuckle under to demands.
[scode type="green"]add insult to injury
To make an unfair or unacceptable situation even worse.
①They told me I was too old for the job, and then to add insult to injury, they refused to pay my expenses!
②Those eyes add insult to injury.