1. 裂缝;裂痕;裂纹
A chink in a surface is a very narrow crack or opening in it.
2. (指从缝隙间透入的光)一束，一缕，一线
A chink of light is a small patch of light that shines through a small opening in something.
3. (使)发出叮当声
When objects chink, or you chink them, they touch each other, making a light ringing sound.
4. (性格或想法的)弱点，缺陷
If you say that someone has a chink in their armour, you mean that they have a small weakness in their character or in their ideas which makes it easy to harm them.