companionate

From companion +‎ -ate.

companionate (comparative more companionate, superlative most companionate)

1. (now historical) Designating a proposed type of marriage (or other partnership) in which the partners plan to have no children and take on no legal obligations to one another. [from 20th c.]
2. Friendly, companionable. [from 20th c.]
3. Pertaining to a (chiefly romantic) relationship that emphasises companionship and mutual respect. [from 20th c.]
   • 2017, Esther Perel, The State of Affairs:

     Gradually it evolved from an economic enterprise to a companionate one—a free-choice engagement between two individuals, based not on duty and obligation but on love and affection.

• companionate marriage