When it comes to finding synonyms for the word "imperishableness", there are a few options to consider. One alternative is "indestructibility", which conveys the same idea of something that is unable to be destroyed or worn down over time. Another option is "permanence", which suggests that something will continue to exist without any changes or decay. "Eternity" can also be used as a synonym, implying that something will last for an infinite amount of time. Lastly, "endurance" is another option that conveys the idea of something that can withstand wear and tear and continue on for a long time.