adj.彻头彻尾的,完全的,臭名昭著
He is an arrant fool.
他是个大傻瓜.
The most arrant nonsense about a product is never questioned.
而且从来没有人对广告中最荒谬绝伦的东西提出过质疑.
That's arrant nonsense.
那完全是一派胡言。