"Unperishably" is a word in ENGLISH

Not subject to death, destruction, or extinction; immortal; undying; imperishable; as, deathless beings; deathless fame.

dî- - A negative prefix similar to the English in- and un-, e.g. dîhímpit— not perfect, imperfect; dî mahinulsúlon—not contrite, …

Not mortal; exempt from liability to die; undying; imperishable; lasting forever; having unlimited, or eternal, existance.

Destined to live in all ages of this world; abiding; exempt from oblivion; imperishable; as, immortal fame.

The quality of being imperishable: indstructibility.

Not perishable; not subject to decay; indestructible; enduring permanently; as, an imperishable monument; imperishable renown.

Not dying; imperishable; unending; immortal; as, the undying souls of men.

Imperishable.