Does the word "Supliferous" exist? If so, do you have a correct spelling of it? I can't find it anywhere, nor a proper definition... What do you think?

Does not exist.

I think you mean 'Superfluous':


serving no useful purpose; having no excuse for being; "otiose lines in a play"; "advice is wasted words"; "a pointless remark"; "a life ...
excess: more than is needed, desired, or required; "trying to lose excess weight"; "found some extra change lying on the dresser"; "yet another book on heraldry might be thought redundant"; "skills made redundant by technological advance"; "sleeping in the spare room"; "supernumerary ...

Perfect!

Thanks!