Definition of "a cappella" 
- (adverb) Music Without instrumental accompaniment.
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..."