What does fax mean?
Fax refers both to a document sent by facsimile transmission and to the process itself, in which a machine scans printed material and transmits it over telephone lines to be reproduced on a receiving device. The word originated as a shortening of 'facsimile', meaning an exact copy, and entered widespread use as fax machines became office staples in the 1980s. It functions as both a noun ('I received a fax this morning') and a verb ('Fax me the details'), with inflected forms such as 'faxed' and 'faxes'. Although email has largely displaced faxing in everyday communication, the word endures in legal, medical, and administrative settings where signed documents must be transmitted quickly and reliably. Today it often evokes nostalgia for late-twentieth-century office culture, yet its persistence in regulated industries makes it a practical vocabulary item rather than a purely historical one.
A document that has been scanned and transmitted over a telephone line, reproduced in print at the receiving end; also the method or apparatus used for such transmission.
"The lawyer sent the signed affidavit by fax within the hour."
Commonly used with modifiers like 'fax machine', 'fax number', and 'fax line'.
To transmit (a document) electronically over a telephone line using a fax machine.
"Kindly fax your completed application form to the admissions office."
Regular plural formed by adding -es after the final x. Note that 'faxes' is also the third-person singular form of the verb 'to fax'.
"The office received dozens of faxes during the busy application season."
The fax machine was invented in 1843 — decades before the telephone — making it older than the technology it ran on for most of its life.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of fax
Fax is a clipped form of 'facsimile', borrowed into English from New Latin 'fac simile', literally 'make similar' or 'make alike', from Latin 'facere' (to make) and 'similis' (like). Facsimile originally denoted an exact reproduction of a document or signature, and the abbreviation 'fax' arose in the twentieth century when telecommunication technology applied the copying concept to transmission over phone lines. The same Latin root 'facere' underlies many English words, including 'fact', 'factory', and 'manufacture'.
Related word forms
How fax is actually used
Once a fixture of office life, 'fax' now carries a slightly dated, bureaucratic connotation, though it remains standard in legal, medical, and government contexts. The verb is fully accepted ('to fax', past tense 'faxed'). The plural is simply 'faxes'.
Easily confused with fax
'Fax' is a document transmission method, while 'facts' are pieces of true information — the two sound nearly identical in some accents but differ entirely in meaning.