Dict: strongs - trustworthy

Strongs:

G281 @ ἀμήν amēn am-ane' Of Hebrew origin [H543]; properly firm that is (figuratively) trustworthy; adverbially surely (often as interjection so be it): - amen verily.

G4101 @ πιστικός pistikos pis-tik-os' From G4102; trustworthy that is genuine (unadulterated): - spike-[nard].

G4103 @ πιστός pistos pis-tos' From G3982; objectively trustworthy; subjectively trustful: - believe (-ing -r) faithful (-ly) sure true.

G571 @ ἄπιστος apistos ap'-is-tos From G1 (as a negative particle) and G4103; (actively) disbelieving that is without Christian faith (specifically a heathen); (passively) untrustworthy (person) or incredible (thing): - that believeth not faithless incredible thing infidel unbeliever (-ing).