A crucial and complex term in Of Grammatology, the “supplement” may be crudely defined as something that is formally outside of a primary term or binary, but that supports or sustains it. Pressure on or exposure of the supplement can thus help to denaturalize or delegitimate the ontological status of the original term, or reveal its internal incompleteness or incoherence. That is why there is political possibility in the supplement.

Wendy Brown, Undoing the Demos, loc. 723