1. 不害怕的：unaffected 不受影响的 | unafraid 不害怕的 | unaided 无助的

2. 不怕的：unaffectedly 自然地 | unafraid 不怕的 | unaided eye 肉眼

3. 无惧的, 不怕的：* crash: 碰撞, 坠落 | * if only: 只要 | * unafraid: 无惧的, 不怕的

4. 不怕的,无惧色的：unafraid 不怕的,无惧色的 | unaware 不知道的,不注意的 | unclean 不干净的,肮脏的

1. 不害怕的；不畏惧的
If you are unafraid to do something, you are confident and not at all nervous about doing it.

e.g. He is a man with a reputation for being tough and unafraid of unpopular decisions...
他作风强悍，作决定不怕得罪人，这是出了名的。
e.g. She was a forceful intellectual unafraid to speak her mind.
她是个很有魄力的知识分子，不惧怕说出自己的想法。

adj

1. free from fear or doubt
easy in mind

e.g. he was secure that nothing will be held against him

Synonym: secureuntroubled