INERRABLE

inerrable, inerrant, unerring

(adjective) not liable to error; “the Church was...theoretically inerrant and omnicompetent”-G.G.Coulton; “lack an inerrant literary sense”; “an unerring marksman”

Source: WordNet® 3.1

Etymology

Adjective

inerrable (comparative more inerrable, superlative most inerrable)

Incapable of error; infallible, unerring.

Source: Wiktionary

In*er"ra*ble, a. Etym: [L. inerrabilis. See In- not, and Err.]

Definition: Incapable of erring; infallible; unerring. "Inerabble and requisite conditions." Sir T. Browne. "Not an inerrable text." Gladstone.

Source: Webster’s Unabridged Dictionary 1913 Edition