What is the origin of the idiom "on good terms" and when to use it?

The origin of this phrase is unclear, but it likely dates back to the 16th century when "terms" referred to agreements or conditions of a contract. Being "on good terms" would mean that both parties were satisfied with the terms of the agreement and had a good relationship with each other. Over time, the phrase evolved to encompass any positive relationship between individuals, not just those based on contractual agreements.

What is the origin of the idiom "on bad terms" and when to use it?

The origin of this idiom is unclear, but it likely comes from the idea of "terms" referring to the conditions or agreements that govern a relationship. When two people are "on bad terms," it suggests that the terms of their relationship are not favorable or agreeable to either party. It is commonly used to describe relationships between individuals or groups that are not in a good state.