apistos

ἄπιστος [5 verses](adj sg fem voc/n0m) "Faithless" is apistos, which means "not to be trusted" "mistrustful," "incredulous," disobedient, "disloyal," or "suspicious."  - The Greek word translated as "faithless" means literally "no faith," but it meant "not to be trusted" and "mistrustful."