Lexical Definition

‎ἄφθαρτος‎ áphthartos (af'-thar-tos) incorruptible ^G:A
from ‎Α‎ (as a negative particle) and a derivative of ‎φθείρω‎

not (in-, un-)corruptible, immortal.

• undecaying (in essence or continuance)

Abbott-Smith

** ἄ-φθαρτος, -ον (< φθείρω), [in LXX: Wi 12:1 18:4*;]
imperishable, immortal;
(a) of things: I Co 9:25, I Pe 1:4, 23 3:4;
(b) of persons: of men, I Co 15:52; of God, Ro 1:23, I Ti 1:17 (MM, s.v.).†

Abbott-Smith References

Liddell-Scott-Jones

ἄφθαρτος-τος, ον,

uncorrupted, undecaying, [Refs 3rd c.BC+]

__II incorruptible, [Refs 4th c.BC+]
__II.2 eternal, [Refs 4th c.BC+]; immortal, πνεῦμα[LXX+1st c.BC+]; of poems, Μοῦσαι[Refs]adverb -τως, τιμᾶν[Refs]

_{LSJ Scripture Refs: Rom.1.23 ☩ 1Cor.15.52}