The distance all the way around the outside of a circle — or of anything round enough that “around” still makes sense: a plate, a tree trunk, a ball, a person’s waist. In maths it is a careful measurement, often written with the letter C, and it is not the same as the line that cuts straight across (that is the diameter) or the line from the centre to the edge (the radius).

The distance all the way around the outside of a circle圓周指的是沿著一個圓形外緣繞一圈的距離──or of anything round enough that "around" still makes sense或是任何圓得夠讓「繞一圈」說得通的東西: a plate, a tree trunk, a ball, a person's waist盤子、樹幹、球、一個人的腰圍。In maths在數學上 it is a careful measurement它是一個精確的測量值, often written with the letter C常常用字母 C 來表示, and it is not the same as而且它和 the line that cuts straight across (that is the diameter)直線橫切過去的那條線（也就是直徑）不一樣, or the line from the centre to the edge (the radius)也和從圓心到邊緣的那條線（半徑）不一樣。

In ordinary talk people stretch it a little: they say “the circumference of the lake” even when the lake is not a perfect circle; they just mean how far it is if you walk the shore all the way around.

In ordinary talk在日常說法裡 people stretch it a little大家會把這個字用得寬鬆一點: they say "the circumference of the lake"他們會說「這座湖的 circumference」 even when the lake is not a perfect circle即使湖並不是一個正圓形; they just mean意思只是 how far it is if you walk the shore all the way around沿著湖岸走一整圈有多遠。

Dictionaries also list a verb, to circumference something, meaning to go around it, but almost nobody uses that verb. People say go around, circle, or walk the edge instead. The noun is the word you will actually meet.

Dictionaries also list a verb字典裡也收錄了一個動詞, to circumference something意思是 circumference 某樣東西, meaning to go around it指繞著它走一圈, but almost nobody uses that verb但幾乎沒有人會用這個動詞。People say go around, circle, or walk the edge instead人們反而會說 go around、circle 或 walk the edge。The noun is the word you will actually meet名詞才是你實際上會遇到的用法。