Collins COBUILD Advanced Learner's English Dictionary - ruinous

1. If you describe the cost of something as ruinous, you mean that it costs far more money than you can afford or than is reasonable. Many Britons will still fear the potentially ruinous costs of their legal system. ADJ: usu ADJ n • ruinously ...a ruinously expensive court case. ADV: ADV adj 2. A ruinous process or course of action is one that is likely to lead to ruin. The economy of the state is experiencing the ruinous effects of the conflict. ADJ: usu ADJ n • ruinously ...cities ruinously choked by uncontrolled traffic. ADV: usu ADV -ed