fiendishly的音標為[?fi?dn??l?] ，基本翻譯為“惡毒地；惡魔似地”，速記技巧為：fiend（惡魔）的副詞形式。

Fiendishly 的英文詞源是 fiend，意為惡魔，加上后綴 -ly，表示副詞，意為“像惡魔般地”。

變化形式：形容詞形式為 fiendish，意為惡魔般的。

相關單詞：

1. fiendishness：惡魔般的本質或特性。

2. devilishly：像惡魔般地。

3. beastly：像野獸般的，殘忍的。

4. monstrous：像怪物般的，巨大的。

5. malignantly：惡意地，惡毒地。

6. fiercely：激烈地，狂熱地。

7. fierceness：激烈的本質或特性。

8. hellishly：像地獄般的，恐怖地。

9. demoniacally：像惡魔般的，狂暴地。

10. fiercenessness：激烈的本質或特性。

以上這些單詞都與 fiendishly 有著相似的含義，表示某種行為或性質具有惡魔般的、激烈的、惡毒的等特征。這些單詞在英語中經常用來形容那些令人恐懼、憤怒、狂熱或殘忍的行為或性質。

常用短語：

1. fiendishly clever

2. devilishly cunning

3. fiercely determined

4. fiercely passionate

5. fiercely attacking

6. fiercely defending

7. fiercely resisting

例句：

1. He is fiendishly clever at maths and always scores top marks in exams.

2. She is devilishly cunning and always manages to get what she wants.

3. He fiercely defended his beliefs even when faced with opposition.

4. She was fiercely passionate about her work and always put in a full days effort.

5. The enemy were fiercely attacking our position, but we were determined to hold on.

6. The fiendishly cunning enemy managed to slip through our defences.

7. She fiercely resisted any attempt to control her and insisted on doing things her way.

英文小作文：

Fiendishly cleverness and passion are the two essential qualities of a true warrior. We must always be determined to pursue our goals, no matter how difficult they may seem, and we must also be passionate about what we do, whether it is writing a book, learning a new language, or anything else.

However, it is not enough just to have these qualities, we must also be able to use them effectively and efficiently. For example, if we are passionate about learning a new language, we must be able to study diligently and persistently, even when faced with difficulties and setbacks. Similarly, if we are determined to achieve our goals, we must be able to plan our strategies carefully, work hard, and never give up until we reach our destination.

In conclusion, fiendishly cleverness and passion are essential for success in any endeavor, but they must be accompanied by effective use of these qualities if we are to achieve our goals and make a real difference in the world.