is used to refer
to a romantic
partner with whom one has a particularly strong bond
. It contrasts with secondary partner
Many polyfolk are uncomfortable with the idea or primary and secondary partners because they don't like the hierarchy it imposes, and because they feel that a secondary is like a second class citizen.
Others are fond of the term because they find the hierarchy matches their actual feelings and/or behavior and communicates clearly that the secondary is in fact not as important as the primary.
I've tried poly relationships with and without an explicit hierarchy and I can't say that either of them works particularly better for me, so I just use whatever terms provide the best map of my current situation.