G0531
ἀπαράβατος
permanent
ἀ-παρά-βατος, -ον (παραβαίνω), inviolable, and so unchangeable: Heb.7:24 (see Westc., in l; Cremer, 653; MM, VGT, see word).† (AS)
Full Thayer's lexicon entry
ἀπαράβατος — aparábatos
ἀπαράβατος, ἀπαράβατον (παραβαίνω), from the phrase παραβαίνειν νόμον to transgress i. e. to violate, signifying either unviolated, or not to be violated, inviolable: ἱερωσύνη unchangeable and therefore not liable to pass to a successor, Heb 7:24; cf. Bleek and Delitzsch at the passage(A later word, cf. Lob. ad Phryn., p. 313; in Josephus, Plutarch, others.)
1 occurrence