pre-noun adjectival
Always used with a negative predicate (ない, いない, etc.) to mean 'no decent ...', 'not a single proper ...'. Expresses strong dissatisfaction or contempt.
この町にはろくなレストランがない。
There isn't a single decent restaurant in this town.
彼はろくな仕事をしない。
He doesn't do any proper work.