/ Dictionary / Index C customs union: Meaning and Definition of Find definitions for: cus'toms un"ion Pronunciation: [key] an association of independent nations or tariff areas created to remove customs barriers between them and to adopt a uniform tariff policy toward nonmember nations. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. customs broker custom-tailor Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language