Strong’s Greek
G4857 — sumphonesis
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
συμφώνησις
sumphonesis — pronounced soom-fo'-nay-sis
from 4856; accordance:--concord. see GREEK for 4856
1 occurrence in the KJV.
2 Corinthians 6:15
And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?