Something that cannot be broken down or disintegrated.

ऐसा कुछ जो टूट नहीं सकता।

English Usage: The old building was deemed undisintegratable, standing strong despite the tests of time.

Hindi Usage: पुरानी इमारत को अटूट माना गया, जो समय की कसौटी पर खड़ी रही।