Polyamory is a type of relationship where an individual has more than one intimate partner at the same time. In this case, all the people in the relationship are transparent about their partners. People who are in this type of relationship are called polyamorous. There are various types of polyamorous relationship based on boundaries an individual set for themselves.
Sources:
https://www.verywellmind.com/what-does-polyamorous-mean-21882