ἄπιστος

apistos

unbelieving

from Α (as a negative particle) and πιστός; (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).

G571

Mark 9:19 · Word #8

Lexicon G571

Lemmaἄπιστος
Transliterationápistos
Strong'sG571
In-contextunbelieving
Literalunbelieving

Morphology ADJ.A VOC F SG All morphology codes

Part of Speech ADJ.A — Attributive Adjective — Describes a noun directly
Case VOC — Vocative — Direct address
Gender F — Feminine — Grammatical feminine
Number SG — Singular — One

Lexical Info

Lemmaἄπιστος
Strong'sG571

SIBI-P1 G571-04

un-faithful one (nominative masculine singular)

Rootἄπιστος (apistos)
Core Meaningsunfaithful, unbelieving, untrusting, unreliable
Semantic Rangewithout faith, not trusting, unbelieving, faithless, unreliable, untrustworthy, outsider to the faith, incredible (of things)
Conceptual SignificanceIn the New Testament, ἄπιστος often contrasts with πιστός (“faithful, believing”), marking the boundary between trust and distrust toward God or Messiah. It can denote moral unreliability, spiritual unbelief, or covenantal non-allegiance, highlighting the centrality of faith/trust in biblical theology.
Morphological NotesAdjective from ἀ- (negative prefix) + πιστός. Forms attested include vocative feminine singular (direct address to an un-faithful woman) and nominative masculine singular (subject or substantive, “an un-faithful man/one”). Functions adjectivally or substantivally.
Rendering RationaleThe term combines the negative prefix ἀ- with πιστός (faithful, trusting, trustworthy), literally meaning “not-faithful” or “without trust.” Rendering it as “un-faithful one” preserves the visible connection to faith/trust (πίστις/πιστός) while the nominative masculine singular form reflects its grammatical use as a substantive adjective referring to a specific person.

AI-generated (openai/gpt-5.2-chat-latest)

Words from Root ἄπιστος (unfaithful, unbelieving, untrusting, unreliable)

SILEX Code Transliteration SIBI-P1
G571-01 apistoi the without-faith ones
G571-02 apistois to the un-faithful ones
G571-03 apiston un-faithful one(s) / un-faithful thing (inflected by case, gender, and number: e.g., "of un-faithful ones" [genitive masculine plural], "an un-faithful thing" [nominative/accusative neuter singular], "an un-faithful woman" [accusative feminine singular],

Word Usage (23 occurrences of G571)

Location Form Transliteration Meaning
Matthew 17:17 ἄπιστος apistos
Mark 9:19 ἄπιστος apistos unbelieving
Luke 9:41 ἄπιστος apistos faithless