/ Dictionary / Index G geosyncline: Meaning and Definition of Find definitions for: ge•o•syn•cline Pronunciation: ( jē"ō-sin'klīn), [key] — n. Geol. a portion of the earth's crust subjected to downward warping during a large span of geologic time; a geosynclinal fold. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. geosynclinal geotaxis Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language