by 1878 [Des Moines Register, May 16], colloquial shortening of telephone (n.), "generally applied to the receiver, but sometimes to the whole apparatus" [Century Dictionary, 1895]. Phone book "publication listing telephone numbers and their associated names" is by 1920; phone booth "small enclosure or stall provided with a public pay-telephone" is by 1906; phone bill "statement of charges for telephone service" is by 1901; phone number (short for telephone number) is by 1906.
mid-12c., "large group of people," from Old French compagnie "society, friendship, intimacy; body of soldiers" (12c.), from Late Latin companio, literally "bread fellow, messmate," from Latin com "with, together" (see com-) + panis "bread," from PIE root *pa- "to feed." Abbreviation co. dates from 1670s.
Meaning "companionship, consort of persons one with another, intimate association" is from late 13c. Meaning "person or persons associated with another in any way" is from c. 1300. In Middle English the word also could mean "sexual union, intercourse" (c. 1300).
From late 14c. as "a number of persons united to perform or carry out anything jointly," which developed a commercial sense of "business association" by 1550s, the word having been used in reference to trade guilds from late 14c. Meaning "subdivision of an infantry regiment" (in 19c. usually 60 to 100 men, commanded by a captain) is from c. 1400.
Meaning "person or persons with whom one voluntarily associates" is from c. 1600; phrase keep company "consort" is from 1560s (bear company in the same sense is from c. 1300). Expression two's company "two persons are just right" (for conversation, etc.), is attested from 1849; the following line varies: but three is none (or not), 1849; three's trumpery (1864); three's a crowd (1856).
word-forming element meaning "voice, sound," also "speaker of," from Greek phōnē "voice, sound" of a human or animal, also "tone, voice, pronunciation, speech," from PIE root *bha- (2) "to speak, say, tell" (source also of Latin for, fari "to speak," fama "talk, report").
"elementary sound of a spoken language, one of the primary elements of utterance," 1866, from Greek phōnē "sound, voice" (from PIE root *bha- (2) "to speak, tell, say").