Someone standing in a place where fear would be normal — a dark road, a high edge, a room full of people — and the fear simply is not switched on. The word is un- laid over afraid, so what you are really looking at is a missing feeling, and the sentence around it usually tells you what should have caused it.
可以想成一個人站在一個本來會讓人害怕的地方。可能是暗暗的路，可能是很高的橋邊，也可能是一屋子的人面前。但害怕那個開關沒有打開。這個字就是 un- 蓋在 afraid 上面，所以你看到的其實是「少了的那個情緒」。句子裡其他部分，通常會告訴你本來該怕的是什麼。從這裡再走一步，就到了第二個用法：既然不怕，那就去做、去問、去講。
From the word’s history
The source gives the word as un- + afraid, so there is nothing hidden inside it: the core is the ordinary word afraid with the negative prefix laid on top.
來源資料寫的是 un- + afraid，所以這個字裡面沒有藏東西：核心就是 afraid 加上一個表示否定的 un-。
Wiktionary etymology supplied in this packet: "From un- + afraid." (source_ref kaikki:3f6f69a190036ae4:1085335473)
登入就可以看每一支怎麼連回核心畫面。