fax vs facsimile machine

fax and facsimile machine both are nouns.

Word	Noun	Adjective	Verb	Adverb
fax	Yes	No	Yes	No
facsimile machine	Yes	No	No	No

As nouns, fax and facsimile machine are synonyms defined as:

fax and facsimile machine: duplicator that transmits the copy by wire or radio

Other synonyms of fax include facsimile.

fax (noun)	facsimile machine (noun)
duplicator that transmits the copy by wire or radio	duplicator that transmits the copy by wire or radio

fax (verb)	facsimile machine (verb)
send something via a facsimile machine