What is "decoherer"

Decoherer \De`co*her"er\ (d[=e]`k[-o]*h[=e]r"[~e]r), n. [Pref. de- + coherer.] (Elec.) A device for restoring a coherer to its normal condition after it has been affected by an electric wave, a process usually accomplished by some method of tapping or shaking, or by rotation of the coherer.