Strong's G3640 — ὀλιγόπιστος (adjective)
oligopistos (ol-ig-op'-is-tos) adj.
1. incredulous, i.e. lacking confidence (in Christ)
[from G3641 and G4102]
KJV: of little faith 
Root(s): G3641, G4102 
Hebrew root: πίστις
Occurrences: 6