coherer

noun

Etymology: Etymology tree Proto-Indo-European *ḱe? Proto-Indo-European *ḱóm Proto-Italic *kom Proto-Italic *kom- Latin con- Latin haereō Latin cohaereōbor. English cohere Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -āriusnom. Latin -āriusbor. Proto-Germanic *-ārijaz Proto-West Germanic *-ārī Old English -ere Middle English -ere English -er English coherer From cohere + -er.

1. A detector of radio waves used in very early radio receivers.

   “Now, this home battery here ready to print is the main steam. The coherer is the valve, always ready to be turned on. The Hertzian wave is the child's hand that turns it.”