Strong's G679 — ἀπταίστος (adjective)
aptaistos (ap-tai'-stos) adj.
1. not stumbling
2. (figuratively) without sin
[from G1 (as a negative particle) and a derivative of G4417]
KJV: from falling 
Root(s): G1, G4417 
Hebrew root: πταίω
Occurrences: 1