Strong's G215 — ἀλάλητος (adjective)
alaletos (al-al'-ay-tos) adj.
1. unspeakable
[from G1 (as a negative particle) and a derivative of G2980]
KJV: unutterable, which cannot be uttered 
Root(s): G1, G2980 
Hebrew root: λαλέω
Occurrences: 1