Useless
Definition 1 of 3
Pro Tip 1/3
Negative Connotation
Use 'useless' to express frustration or disappointment in something's performance. Buying that cheap vacuum was useless; it doesn't clean at all.
Pro Tip 2/3
Unhelpful Efforts
Use 'useless' when someone's attempt to help has no positive outcome or makes no difference. I know you tried to fix the leak, but it was a useless effort.
Pro Tip 3/3
Extent of Uselessness
Combine 'useless' with words like 'completely' or 'utterly' to stress the total lack of effectiveness. His advice was utterly useless in that situation.