Lexical Definition

‎ἀπιστία‎ apistía (ap-is-tee'-ah) unbelief G:N-F
from ‎ἄπιστος‎

unbelief.

Usage: 4 forms in 11 verses
Form Translated As     In Verse(s)
ἀπιστίᾳ in unbelief Rom.11.23
through unbelief Rom.4.20
unbelief Mark.9.24 • Rom.11.20 • 1Tim.1.13
ἀπιστίασ of unbelief Heb.3.12
ἀπιστίαν unbelief Matt.13.58 • Mark.6.6 • Mark.16.14 • Heb.3.19
ἀπιστία unbelief Rom.3.3

Abbott-Smith

** ἀπιστία, -ας, ἡ (< ἄπιστος), [in LXX: Wi 14:25, IV Mac 12:4*;]
want of faith, unbelief: Mt 13:58, Mk 6:6 9:24 16:14, Ro 3:3 (but v.s. ἀπιστέω) Ro 4:20 11:20, 23, I Ti 1:13, He 3:12, 19 (DCG, ii, 775a; Cremer, 492).†

Abbott-Smith References

Book Refs
Matthew 13:58
Mark 6:6 · 9:24 · 16:14
Romans 3:3 · 4:20 · 11:20 · 11:23
1 Timothy 1:13
Hebrews 3:12 · 3:19

Liddell-Scott-Jones

ἀπιστία,

Ionic dialect -ίη, ἡ, unbelief, distrust, πίστεις.. δμῶς καὶ ἀπιστίαι ὤλεσαν ἄνδρας beliefs and disbeliefs, [Refs 8th c.BC+]; ὑπὸ ἀ. μὴ γενέσθαι τι from disbelief that.., [Refs]; ἀ. πρὸς ἑαυτόν lack of self-confidence, [ἀπιστίας 4th-5th c.BC: Aeschylus Tragicus “Agamemnon” 268">Refs 5th c.BC+]; ἀπιστίαν ἔχειν περί τινος to be in doubt, [Refs 5th c.BC+]; πρὸς -ίαν τοῦ κατηγόρου to discredit him, [Refs 5th c.BC+]

__2 of things, τὰ εἰρημένα ἐς ἀ. πολλὴν ἀπῖκται[Refs 5th c.BC+]; πολλὰς ἀπιστίας ἔχει it admits of many doubts, [Refs 5th c.BC+]; ἀτοπία καὶ ἀπιστία incredibility, [ἀπιστίαν ἔχει 4th c.BC: Demosthenes Orator 10.44. ">Refs 5th c.BC+]
__II want of faith, faithlessness, θνήσκει δὲ πίστις βλαστάνει δ᾽ ἀ.[Refs 5th c.BC+]; treachery, [ἀπιστίαν 5th c.BC: Eupolis Comicus 309.">Refs 5th c.BC+]