noun

• A thing that has been reconstructed or restored to an earlier state.
• The act of restoring something to an earlier state.
• A result of an attempt to understand in detail how a certain result or event occurred.
• (linguistics) A result of linguistic reconstruction; a model representing an unattested linguistic unit: a phoneme, a morpheme or a word.
• A period of the history of the United States from 1865 to 1877, during which the nation tried to resolve the status of the ex-Confederate states, the ex-Confederate leaders, and the Freedmen (ex-slaves) after the American Civil War.