- extension (n.)
[extension 词源字典]
- c. 1400, "swelling, bulging," from Latin extensionem/extentionem (nominative extensio/extentio) "a stretching out, extension," noun of action from past participle stem of extendere (see extend). In a concrete sense, "extended portion of something" (a railroad, etc.), from 1852. Telephone sense is from 1906. [extension etymology, extension origin, 英语词源]