R0342100 (ro͞o′ə-nəs)adj.1. Causing or apt to cause ruin; destructive: a ruinous habit; a ruinous rivalry.2. Falling to ruin; dilapidated or decayed.ru′in·ous·ly adv.ru′in·ous·ness n.Thesaurus
Adv.
1.
ruinously - in a ruinous manner or to a ruinous degree; "ruinously high wages"