An anchor partner is an emotional support partner with whom you have a strong connection and helps ground and balance you. An anchor partner may or may not be a nesting partner, romantic partner or sexual partner.
Poly.Land: What is an Anchor Partner
Polyamory weekly article: A Replacement for Primary/Secondary
Compersion (Noun) – The state of being happy for another person’s happiness. Often used to describe being happy at seeing one’s romantic partner experiencing happiness with other partners.
Chris and Dotty are romantic partners. Dotty is also romantically involved with Stan. Chris feels compersion when he sees how happy Dotty is with Stan.
A relationship style which emphasizes frequent interactions between metamours. The term describes the idea that all of the people involved in the poly relationships would be comfortable sitting around the kitchen table, like a family.
Metamorsel (noun) – A metamour you find particularly attractive.
Chris is in a romantic relationship with Diva. Dennis is also in a romantic relationship with Chris. Diva looks like a very hot metamorsel in her purple corset.
Metamour (noun) – Your lover’s lover. In polyamory you may have a romantic relationship with someone who has more than one ongoing romantic relationship. Someone that your romantic partner is in such a relationship with, but you are not, is a Metamour.
Chris is in a romantic relationship with Jenny. Diva is also in a romantic relationship with Chris. Diva and Jenny are just metamours.
A nesting partner is one that you share living space with. This may or may not include: owning property, sharing finances, or raising children. It is possible to have multiple nesting partners, and multiple nests (homes).
New relationship energy (NRE), is a euphoric emotional state associated with the early phase of a romantic relationship.
Paramour (noun) – A lover. In polyamory you may have a romantic relationship with one or more lovers. Those lovers may or may not have romantic or platonic relationships with each other.
Chris is in a romantic relationship with Dottie, and Chris is also in a romantic relationship with Dennis, Dawn, and Diva. All of them are Chris’ Paramours.
Polyamorist (noun) – A person who practices polyamory.
Dennis is married to Dawn. Dennis and Dawn are both romantically involved with Chris. Dennis, Dawn, and Chris are all polyamorists.
Polyamory (noun) – The practice of having, or being open to having, more than one romantic partner. Polyamory is typically characterized as consensual non-monogamy, where all partners involved enter into the arrangement as an explicit choice.
Dennis is married to Dawn, but also is romantically involved with Chris. Dawn has full knowledge of the relationship between Dennis and Chris and Chris knows that Dennis and Dawn are married.
Polyamory on Wikipedia