Music Without instrumental accompaniment. (adverb)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "a cappella" in a sentence
"Next morning outside the hotel two ancient sisters in long overcoats, one tall, one short, stand on the pavement singing folksongs in a cappella harmony."
"The lyrics to one of my favorite songs, More Than a Paycheck, by the a cappella group Sweet Honey in the Rock, go like this: We bring more than a paycheck to our loved ones and families..."