Exact historical dictionary sense
Incredible in Webster's 1913 dictionary
The 1913 record labels incredible as adjective. Its source-bounded etymology and selected historical definition appear below.
[L. incredibilis: cf. OF. incredible. See In- not, and Credible.]
Cross-verified historical senseIn Webster's Revised Unabridged Dictionary (1913), "incredible" is labeled adjective. Its etymology is recorded as: "[L. incredibilis: cf. OF. incredible. See In- not, and Credible.]" The selected historical definition says: "Not credible; surpassing belief; too extraordinary and improbable to admit of belief; unlikely; marvelous; fabulous."