analog-to-digital convertern. Abbr. ADC An electronic device that takes an electrical signal as an input, and yields a digital output signal representing the strength of the source signal, commonly used for recording digital audio. Also called A/D converter.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.