General:
* Circle back: To return to a topic or issue later.
* Come full circle: To return to a starting point, often after a long journey or process.
* Circle of life: The continuous cycle of birth, growth, death, and renewal.
* Circle of friends: A group of close friends.
* Run in circles: To be busy but unproductive.
* Square circle: An impossibility or a contradiction in terms.
Geometric:
* Circle of radius: The distance from the center of a circle to its edge.
* Circle of circumference: The distance around the outside of a circle.
* Circle of diameter: The distance across a circle through its center.
* Circle of arc: A portion of the circumference of a circle.
Figurative:
* Circle of trust: A group of people who are trusted with confidential information.
* Circle of influence: The range of people or events that one can affect.
* Circle of responsibility: The scope of tasks or duties that one is accountable for.
* Circle of power: A group of people who hold significant influence or authority.
Idioms:
* Go around in circles: To make no progress, to be stuck in a repetitive cycle.
* Throw someone in a circle: To confuse or disorient someone.
* Out of the circle: To be excluded from a group or activity.
* Square peg in a round hole: A person who is not suited for a particular job or role.
Specific to a particular context:
* Circle of light: A beam of light emitted from a source.
* Circle of support: A group of people who provide emotional or practical assistance.
* Circle of learning: A group of people who are engaged in a shared learning experience.
* Circle of safety: A designated area where people feel safe and protected.
This is not an exhaustive list, but it provides a variety of phrases with the word "circle" to help you understand its different meanings and uses.