If something is indivisible, it cannot be cut into parts — or it must not be, because breaking it would destroy what it is. There are three places you meet it.

If something is indivisible如果某樣東西是 indivisible, it cannot be cut into parts它就不能被切成好幾份 — or it must not be或者說不該被切開, because breaking it would destroy what it is因為切開就會毀掉它原本的樣子。There are three places you meet it你會在三個地方遇到這個字。

In mathematics and older science it means 'cannot be divided': the ancient idea of the atom was of an indivisible piece of matter, the smallest thing there is.

In mathematics and older science在數學和早期科學裡, it means 'cannot be divided'它的意思是「不能再分割」: the ancient idea of the atom was of an indivisible piece of matter古代對原子的想法就是一種不可再分割的物質, the smallest thing there is是最小的存在。

In politics it is a solemn word for a country or a group that must stay as one: the American Pledge of Allegiance says 'one Nation under God, indivisible'.

In politics在政治上, it is a solemn word for a country or a group that must stay as one它是形容一個國家或團體必須維持統一、不可分割的莊重用字: the American Pledge of Allegiance says 'one Nation under God, indivisible'美國效忠誓詞裡就說「one Nation under God, indivisible」。

And in more everyday serious writing it links two things so tightly that you cannot have one without the other — 'freedom and responsibility are indivisible', meaning you never get one alone. That third use is the most useful for a student, and note what it really claims: not that the two things are the same, but that they cannot be separated.

And in more everyday serious writing而在比較日常一點的正式寫作裡, it links two things so tightly that you cannot have one without the other它把兩件事綁得緊緊的，讓你不能只有其中一個 — 'freedom and responsibility are indivisible'像「freedom and responsibility are indivisible」, meaning you never get one alone意思是你永遠不會只單獨擁有其中一個。That third use is the most useful for a student這第三種用法對學生最有用, and note what it really claims要注意它真正在講的是什麼: not that the two things are the same不是說這兩件事是同一件事, but that they cannot be separated而是說它們無法被拆開。

The word is formal. Nobody says 'this cake is indivisible' at a birthday party. It belongs in law, politics, philosophy, and mathematics.

The word is formal這個字很正式。Nobody says 'this cake is indivisible' at a birthday party沒有人會在生日派對上說「這個蛋糕是 indivisible 的」。It belongs in law, politics, philosophy, and mathematics它是屬於法律、政治、哲學，和數學裡的用字。

It is also, rarely, a noun — 'an indivisible' meaning a thing that cannot be divided — but you can safely learn it as an adjective and leave the noun alone.

It is also, rarely, a noun它也可以很少見地當名詞用 — 'an indivisible' meaning a thing that cannot be divided「an indivisible」指的是無法被分割的東西 — but you can safely learn it as an adjective and leave the noun alone但你完全可以只學形容詞用法，不用管這個名詞。