boundary term

noun2

1. •
   A term that must be added to an equation to represent a boundary condition.

   • If M is truncated to have toral boundary, there will be a boundary term after the integration by parts step. — 1996
2. •
   A word or phrase that is used for othering; a term that serves to identify someone or something as other than the speaker.

   • 'Sustainability' is a boundary term, signifying complex interactions between science, politics, policy making and development (Scoones, 2010: 153-4). — 2013