1. Mil.an area in a theater of operations where combat forces operate, extending typically from the front line to the communications zone.
2. Slang.an area in some cities, usually in an older midtown section, where pornography stores, striptease bars, etc., flourish, or are tolerated because of being concentrated in one district.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.