Strong's G412 — ἀνεκλάλητος (adjective)
aneklaletos (an-ek-lal'-ay-tos) adj.
1. not spoken out
2. (by implication) unutterable
[from G1 (as a negative particle) and a presumed derivative of G1583]
KJV: unspeakable 
Root(s): G1, G1583 
Hebrew root: ἐκλαλέω
Occurrences: 1