"Liftable" means capable of being lifted, but some antonyms for this word could be "immobile," "stationary," or "fixed." These words imply that an object or item cannot be moved easily or lifted at all. Other antonyms for "liftable" could include "unyielding," "unbendable," or "rigid," suggesting that an object is not flexible or pliable enough to be lifted. Additionally, "immoveable," "unchangeable," and "static" convey a sense of permanence or steadfastness that is incompatible with the idea of being lifted. Overall, antonyms for "liftable" suggest the absence of mobility or flexibility.