long-wave

The compound "long-wave" is a modern technical term formed from two native English elements. "Long," with its Proto-Germanic root langgaz, has consistently denoted physical or temporal extension. "Wave," from the Old English verb wafian meaning to fluctuate or move to and fro, evolved to describe the oscillating motion characteristic of water and, by scientific analogy, electromagnetic radiation. In the late 19th century, as the electromagnetic spectrum was categorized, "long-wave" was coined through straightforward descriptive compounding to designate radio signals with a comparatively long wavelength (and consequently low frequency), distinguishing them from medium-wave and short-wave bands used in broadcasting and communication.

Structure: long (extended in duration or length) + wave (a periodic disturbance) - long: From Old English lang, long, of Germanic origin; related to Dutch lang and German lang. Functions as an adjective describing extent. - wave: From Old English wafian 'to wave with the hands', of Germanic origin. Functions as a noun denoting a periodic disturbance.