Incredible
From BiblePortal Wikipedia
Vine's Expository Dictionary of NT Words [1]
1: Ἄπιστος (Strong'S #571 — Adjective — apistos — ap'-is-tos )
is once rendered "incredible," Acts 26:8 , of the doctrine of resurrection; elsewhere it is used of persons, with the meaning "unbelieving." See Belief , C, Note (3).
King James Dictionary [2]
INCRED'IBLE, a. L. incredibilis in and credibilis, credible.
That cannot be believed not to be credited too extraordinary and improbable to admit of belief.
Why should it be thought a thing incredible with you, that God should raise the dead? Acts 26
Webster's Dictionary [3]
(a.) Not credible; surpassing belief; too extraordinary and improbable to admit of belief; unlikely; marvelous; fabulous.