Wiktionary
unliftable
a. Impossible to lift.
Usage examples of "unliftable".
That was a power beyond anything human, Owen thought, and until he found something within the human world to match that power, the craft would sit motionless inside the darkness of the hangar, as heavy and unliftable as his dream of making a mark in the world.
He understood the enormity the minute the delivery man arrived at the flat with four unliftable cases.