Lexical Definition

‎ἀπαράβατος‎ aparábatos (ap-ar-ab'-at-os) permanent ^G:A
from ‎Α‎ (as a negative particle) and a derivative of ‎παραβαίνω‎

unchangeable.

• not passing away, i.e. untransferable (perpetual)

Abbott-Smith

*† ἀ-παρά-βατος, -ον (< παραβαίνω),
inviolable, and so unchangeable: He 7:24 (v. Westc., in l.; Cremer, 653; MM, VGT, s.v.).†

Abbott-Smith References

Liddell-Scott-Jones

ἀπαράβατος-βᾰτος, ον,

unalterable, εἱρμὸς αἰτιῶν[Refs 1st c.BC+]; infallible, προρρήσεις[Refs 3rd c.AD+]; also of persons, [Refs]adverb -τως Chrysippsipp.[Refs]

__2 inviolable, κύρια καὶ ἀ.[Refs 1st c.BC+]
__3 permanent, perpetual, ἱερωσύνη[NT]
__3 active, not transgressing, [Refs 1st c.AD+] adverb -τως[Refs 2nd c.AD+]

_{LSJ Scripture Refs: Heb.7.24}