adjective

incapable of producing any useful result; pointless.

a futile attempt to keep fans from mounting the stage

fruitless,vain,pointless,useless,worthless,ineffectual,ineffective,inefficacious,to no effect,of no use,in vain,to no avail,unavailing,unsuccessful,failed,thwarted,unproductive,barren,unprofitable,abortive,impotent,hollow,empty,forlorn,idle,sterile,nugatory,valueless,hopeless,doomed,lost,no good to gundy,bootless