Loco is an informal, slightly playful way to say crazy — not a careful medical word, and not polite in a serious conversation about someone’s mind.

Loco瘋了、神經 is an informal, slightly playful way to say crazy是一種非正式、帶點開玩笑意味，用來說「瘋了」的講法 — not a careful medical word,不是嚴謹的醫學用語， and not polite in a serious conversation about someone's mind在認真討論一個人的精神狀態時也不禮貌。

English borrowed the adjective from Spanish loco, “insane” or “crazy.” You will hear it in American English more than in careful British English: go loco, a loco idea. It can be affectionate teasing among friends, or a bit rude if you aim it at a person who did not ask for the joke.

English英文 borrowed the adjective借用了這個形容詞， from Spanish loco,來自西班牙文的 loco， "insane" or "crazy."意思是「瘋狂」或「發瘋」。You will hear it你會聽到這個字 in American English more than in careful British English:在美式英文比在正式的英式英文更常出現： go loco, a loco idea像 go loco（發瘋）、a loco idea（瘋狂的點子）。It can be affectionate teasing among friends,它可以是朋友之間帶點感情的調侃， or a bit rude也可能有點失禮， if you aim it at a person who did not ask for the joke如果你拿它去說一個沒打算被開玩笑的人。

Though actually, English also has loco as a short form of locomotive, the train engine; that is a different word in real life, even if it looks the same on the page.

Though actually,不過實際上， English also has loco英文裡還有另一個 loco， as a short form of locomotive, the train engine;是 locomotive（火車頭）的簡稱； that is a different word in real life,實際上是完全不同的字， even if it looks the same on the page就算寫出來看起來一樣。

For this sense, think “wild in the head,” not “train.”

For this sense,就這個意思來說， think "wild in the head,"要想的是「腦子瘋狂」， not "train."而不是「火車」。