infidel 0571 - apistos {ap'-is-tos}; from 0001 (as a negative particle) and 4103; (actively) disbelieving, i.e. without Christian faith (specially, a heathen); (passively) untrustworthy (person), or incredible (thing): -- that believeth not, faithless, incredible thing, {infidel}, unbeliever(-ing).
infidelity 02184 ## z@nuwth {zen-ooth'} ; from 02181 ; adultery , i . e . (figuratively) {infidelity} , idolatry : -- whoredom .