adj.残酷的;刁钻的;非常不愉快的;(困难、机敏等)非常的;
例句:
Business competition can be fiendish at times.
商业竞争有时是很惨烈的.
Don't be so fiendish . A fiendish person is never welcomed.
你不要那么凶,凶横的人一向不受欢迎.
This was a fiendish act of wickedness.
这是极其恶毒的行为。