You use downright to emphasize unpleasant or bad qualities or behaviour.
例句
...ideas that would have been downright dangerous if put into practice...如果付诸实践就会极度危险的想法She was often downright rude to him.她常对他十分粗鲁。
英汉词典释义
adv.
完全地
That road is downright dangerous!那条路危险透顶！
adj.
彻底的, 完全的
He wasn’t just impolite—he was downright rude.他不仅仅是不礼貌，而是无礼透顶。His evidence was a blend of smears, half truths and downright lies.他的证词里掺杂着诽谤、部份的事实和彻头彻尾的谎言。
英英词典释义
Adjective
1. characterized by plain blunt honesty;
"a downright answer""a downright kind of person"
2. complete and without restriction or qualification; sometimes used informally as intensifiers;
"absolute freedom""an absolute dimwit""a downright lie""out-and-out mayhem""an out-and-out lie""a rank outsider""many right-down vices""got the job through sheer persistence""sheer stupidity"