That which builds again from what remains. Reconstruction is inference disciplined by evidence, and never the original.
An agent noun built on reconstruct, from Latin construere (to pile up, to build): com- (together) + struere (to build); a reconstructor is named for the rebuilding, not for what it rebuilds.
That which builds again from what remains. Its rebuilding stays disciplined by evidence, and what it produces is never mistaken for the original it is standing in for.