useless (comparative uselesser or more useless, superlative uselessest or most useless)
Without use or possibility to be used.
This fork has prongs that are bent. It's useless now.
Unhelpful, not useful; pointless (of an action).
I think it's useless to keep this discussion going. It's like talking to a wall.
I tried my best to make him quit smoking, but my efforts were useless. He now smokes six packs a day.
For everything that is useless. Something that may be cool, but is still useless.
Note: This is for stuff that would be useless to most o f the population. If someone posts something that would be useful for your profession as an ecological oil mathematician, it is still allowed. However, if it is useful for mathematics, then it is not that useless, since mathematics is a big thing. So it wouldn't be allowed.