/ Dictionary / Index V variable region: Meaning and Definition of Find definitions for: var'iable re"gion Pronunciation: [key] — Immunol. Immunol. a configuration in the upper branches of theof an antibody molecule, unique in each antibody type, that binds with the determinant of a specific antigen. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. variable-rate variable star Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language