Strong’s Greek
G1421 — dusermeneutos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
δυσερμήνευτος
dusermeneutos — pronounced doos-er-mane'-yoo-tos
from 1418 and a presumed derivative of 2059; difficult of explanation:--hard to be uttered. see GREEK for 1418 see GREEK for 2059
1 occurrence in the KJV.
Hebrews 5:11
Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.