Definition from Wiktionary, the free dictionary
- A rite of purification, especially washing.
- The restoration of credibility to a government by the purging of perpetrators of crimes committed under an earlier regime.
Derived terms 
Related terms 
- lustrate ("to purify (transitive)").
- 1904 (Merriam) Webster's International Dictionary of the English Language says: "a sacrifice, or ceremony, by which cities, fields, armies, or people, defiled by crimes, pestilence, or other cause of uncleanness, were purified," from which the derivation of both meanings can be inferred.
- Lustration in the 1911 Encyclopædia Britannica.
- Tiscali's "Difficult Words" dictionary discusses the word here, also primarily referring to meaning 1).
- A "classic" article on 2) lustration appears on Beyond Intractability.
- Wikipedia (English) says "In the period after the fall of the various European Communist states in 1989–1991, the term came to refer to the policy of limiting the participation of former communists, and especially informants of the communist secret police, in the successor governments or even in civil service positions."
- Lustratio in A Dictionary of Greek and Roman Antiquities, John Murray, London, 1875