An accompaniment is an action or thing that goes along with another one. For example, music is an accompaniment to dance.
You might have noticed how many things go together perfectly when you're at a restaurant. The food and drinks are an accompaniment to the nice table setting and friendly service. If someone is walking their dog on a Saturday morning, taking a walk with them can be an accompaniment to their exercise routine.
A part, usually performed by instruments, that gives support or adds to the background in music, or adds for ornamentation; also, the harmony of a figured bass.
