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Definition
extension   Show phonetics
noun [C]
1 PART OF A BUILDING a new room or rooms that are added to a building
You could build an extension onto the back of the house.

2 EXTRA TIME extra time that you are given to do or use something
You might be able to get an extension on your visa.

3 TELEPHONE a telephone that is connected to the main telephone in an office or other large building
Call me on extension 213.

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