The term 'Ring of Chain' is a metaphor for a situation in which one person or group is connected to another in a way that cannot be broken. The term is often used to describe relationships between people, such as a marriage, or between countries, such as an alliance. In this crossword, the solution for the term 'Ring of Chain' is the word 'LINK, ' which is a four-letter word. LINK is a verb meaning to connect two things together, and it is also a noun meaning a connection between two people or things. Therefore, the term 'Ring of Chain' can be summarized as a metaphor for a strong connection between two people or groups that cannot be broken.