uselessWe have cleared out carloads of useless junk.
no useMoney is no use if it's just sitting there.
serve no purposeSuch warnings serve no purpose other than to scare the public.
pointlessShe sees cleaning as a pointless exercise since everything is going to get dirty again.
worthlessThe majority of objects in the exhibition are worthless junk.
meaninglessPolls are meaningless this early on in an election campaign.
futileShe had made several futile attempts to lose weight.
unhelpfulI wish he would keep his unhelpful comments to himself.
ineffectualformalHe made an ineffectual attempt to regain his throne.
inefficientTraditional irrigation systems are inefficient because they waste a third of the water they spray on fields.