Antonyms of adj reusable

1 sense of reusable

Sense 1
reclaimable, recyclable, reusable -- (capable of being used again)

INDIRECT (VIA useful) -> useless -- (having no beneficial use or incapable of functioning usefully; "a kitchen full of useless gadgets"; "she is useless in an emergency")

Similarity of adj reusable

1 sense of reusable

Sense 1
reclaimable, recyclable, reusable -- (capable of being used again)
       => useful (vs. useless), utile -- (being of use or service; "the girl felt motherly and useful"; "a useful job"; "a useful member of society")