without results or success

bringing no advantage, product

(of an action) of no use; having no effect

hopeless, pointless

not producing the effect(s) desired

useless

(of) an animal without a backbone or spinal column, e.g. insects, worms

weak, useless

with little or no sense, aim or purpose

ridiculous, senseless

not working; not valuable

not working; not valuable

not able to produce offspring, fruit etc; without a productive purpose; producing nothing; free from living germs

unproductive, clean

without effect or success

futile

not productive

idle, non-productive

having no use; not able to do what is intended; having no result

not working; not valuable