ext
n. countable B1 Intermediate ext
n. a short way of writing the word 'extension'. You see this most often in phone numbers or at the end of computer files.
n. a standard abbreviation for 'extension'. Refers to an internal telephone line or a suffix at the end of a computer file name.
Call me at 555-0199, ext. 42.
The receptionist asked for the specific ext. to direct the call to the accounting department.
When configuring the server, ensure that the file ext. is correctly mapped to the appropriate application to prevent execution errors.
Usage
Typically written with a period (ext.) when used as an abbreviation in formal or business contexts.