twilight zone(redirected from twilight zones)
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1. an area of a city or town, usually surrounding the central business district, where houses have become dilapidated
2. the lowest level of the ocean to which light can penetrate
twilight zone[′twī‚līt ‚zōn]
That zone of the earth or other planet in twilight at any time.
Anything resembling the twilight zone of the earth, as the narrow sector on each side of the equisignal zone of a four-course radio range station, in which one signal is barely heard above the monotone on-course signal.