/ Dictionary / Index Z zone system: Meaning and Definition of Find definitions for: zone' sys"tem Pronunciation: [key] — Photog. Photog. a system for envisioning the values to appear in a black-and-white print and for determining exposure and development, based on a scale of shades ranging from 0 (black) to IX (white). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. zone plate zone time Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language