Clearing

Clearing is the "[r]emoval of data from an IS, its storage devices, and other peripheral devices with storage capacity, in such a way that the data may not be reconstructed using common system capabilities (i.e., keyboard strokes); however, the data may be reconstructed using laboratory methods. Cleared media may be reused at the same classification level or at a higher level. Overwriting is one method of clearing."

Source
National Information Systems Security (INFOSEC) Glossary (NSTISSI No. 4009 Sept. 2000).