Trace

Trace can be seen as an always contingent term for a "mark of the absence of a presence, an always-already absent present", of the ‘originary lack’ that seems to be "the condition of thought and experience". Trace is a contingent unit of the critique of language always-already present: “language bears within itself the necessity of its own critique”[2]. Deconstruction, unlike analysis or interpretation, tries to lay the inner contradictions of a text bare, and, in turn, build a different meaning from that: it is at once a process of destruction and construction. Derrida claims that these contradictions are neither accidental nor exceptions; they are the exposure of certain “metaphysics of pure presence”, an exposure of the “transcendental signified” always-already hidden inside language. This “always-already hidden” contradiction is trace.

Wikipedia article (orphaned) on trace according to Derrida