- 1
A no-brainer is a choice so easy that you hardly need to think. People say it when they want to stress that the answer is obvious: taking the paid job over the unpaid one was a no-brainer. It is informal, common in speech and in light news, and a little American in flavour, though lots of English speakers use it now. You would not put it in a very serious essay. Though actually, it does not mean the person has “no brain” — it means the problem does not need much brain. The -er makes a noun for the thing itself, the easy decision.
想都不用想的事；顯而易見的決定（不是罵人沒大腦）
組成From no + brain + -er: “something that needs no brain”.
同家族的字
- brainthe middle piece; a no-brainer is a thing that needs almost no brainwork
原始詞典資料2 筆記錄
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。
no-brainernoun
- 1
informalAn easy or obvious conclusion, decision, solution; something requiring little or no thought.
- Choosing the older version which was as good as the newer version for half the cost was a no-brainer.
- "Babcock [an engineering services company with a facility at Rosyth] has new contracts for new frigates there, so opening up the opportunities for rail running in is a no-brainer."
- 2
informalA conundrum requiring little or no thought to solve; A problem with an easy or obvious conclusion, decision, solution.
- This next exam question is a no-brainer.
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。