Strong’s Greek
G97 — adolos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
ἄδολος
adolos — pronounced ad'-ol-os
from 1 (as a negative particle}; and 1388; undeceitful, i.e. (figuratively) unadulterated:--sincere. see GREEK for 1 see GREEK for 1388
1 occurrence in the KJV.
1 Peter 2:2
As newborn babes, desire the sincere milk of the word, that ye may grow thereby: