adjective (written)
1 costing a lot of money and more than you can AFFORD:
ruinous legal fees * They were forced to sell out at a ruinous loss.
2 causing serious problems or damage:
The decision was to prove ruinous. * Such action would be ruinous to her career. * a ruinous mistake / gamble
3 (formal) (of a town, building, etc.) destroyed or severely damaged:
a ruinous chapel * The buildings were in a ruinous state.
ruinously adverb:
ruinously expensive
