extension/ɪk'sten∫ən/

n.

➊ the act of making sth longer or larger

➋ a telephone that is connected to a central system of a large building

n.

➊ [U; C] 延伸；扩大：[extension of sth] The extension of the highway to the town will benefit more than 50,000 people. 高速公路延伸至这个镇上将使5万多人受益。

➋ [C] 分机：What's your extension number? 你的分机号码是多少？

构词extend + -sion

音组-ension/-'en∫ən/

comprehension; dimension; extension; pension; suspension; tension