1 [mass noun] the action or process of reconstructing or being reconstructed:the economic reconstruction of Russia
[count noun] a thing that has been rebuilt after being damaged or destroyed:comparison between the original and the reconstruction
[count noun] an impression, model, or re-enactment of a past event formed from the available evidence:a reconstruction of the accident would be staged to try to discover the cause of the tragedy
2 (the Reconstruction) the period 1865–77 following the American Civil War, during which the Southern states of the Confederacy were controlled by federal government and social legislation, including the granting of new rights to black people, was introduced.
reconstruction in other Oxford dictionaries
Definition of reconstruction in the US English dictionary