A yo-yo is a toy: two round discs joined in the middle with a string wound between them. You hold the end of the string, drop it, and the toy runs down and climbs back up to your hand. Skilled players do tricks with it.

A yo-yo is a toyyo-yo是一種玩具: two round discs joined in the middle with a string wound between them兩個圓盤在中間連接，中間繞著一條繩子. You hold the end of the string你抓住繩子的一端, drop it讓它落下, and the toy runs down and climbs back up to your hand玩具就會往下滑再爬回你手上. Skilled players do tricks with it厲害的玩家會用它耍花招

The word is also used as a verb — if a number or a person yo-yos, it goes up and down, up and down: "His weight yo-yoed for years." You will hear yo-yo dieting for losing weight and putting it back on again and again, and prices can yo-yo too.

The word is also used as a verb這個字也可以當動詞用 — if a number or a person yo-yos如果一個數字或一個人yo-yos（忽上忽下）, it goes up and down, up and down意思是它一直上上下下: "His weight yo-yoed for years.""His weight yo-yoed for years."（他的體重多年來忽胖忽瘦。） You will hear yo-yo dieting你會聽到yo-yo dieting for losing weight and putting it back on again and again指一再減重又復胖, and prices can yo-yo too而價格也可以yo-yo（忽漲忽跌）

In American English, calling a person a yo-yo is an old, mild insult meaning a fool.

In American English在美式英語裡, calling a person a yo-yo稱一個人是yo-yo is an old, mild insult meaning a fool是一種古老、輕微的侮辱，意思是傻瓜

The word began as a brand name, but nobody feels it as a brand now; it is just the ordinary word for the toy, which is why you usually see it with a small y.

The word began as a brand name這個字原本是品牌名, but nobody feels it as a brand now但現在沒有人把它當品牌感覺了; it is just the ordinary word for the toy它就只是這種玩具的普通名稱, which is why you usually see it with a small y這也是為什麼你通常會看到它用小寫y