useless
/ˈjuːs.ləs/
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.
(of a person) Good-for-nothing; not dependable.
Bill never mows the lawn, takes out the trash or anything. He's useless, but I love him anyways.
(of a person) Unable to do well at a particular task or thing. Useless is mildly insulting.
My brother is useless at most computer games, but he is an awesome PS2 player.