A way to picture it: someone acting without stopping to think first — not because they can't think, but because in that moment they didn't. Sometimes that means a bad decision; sometimes it just means looking silly in front of other people.
Two branches
沒想清楚（判斷上的傻）
核心畫面裡「沒先想後果」的那一面，落在決定、說法、計畫上。
not sensible · adjective · B2
Not sensible, and showing that someone was not thinking carefully about what could happen. Used about the things people do and say — an action, a remark, a choice or a plan.
愚蠢的；不明智的
在人前顯得傻
同一個「傻」的畫面轉向旁人的眼睛：不是後果有多糟，而是當下在別人面前的樣子。
looking silly · adjective · B2
Behaving in a silly way, or seeming silly to the people who can see you. Often used about how someone looks or feels in a moment in front of others.
傻的；出糗的
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
foolishlyadv/ˈfuːlɪʃli/
In a foolish manner.
Without good judgment.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。