Strong’s Greek
G412 — aneklaletos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
ἀνεκλάλητος
aneklaletos — pronounced an-ek-lal'-ay-tos
from 1 (as a negative particle) and a presumed derivative of 1583; not spoken out, i.e. (by implication) unutterable:--unspeakable. see GREEK for 1 see GREEK for 1583
1 occurrence in the KJV.
1 Peter 1:8
Whom having not seen, ye love; in whom, though now ye see him not, yet believing, ye rejoice with joy unspeakable and full of glory: