facebook n.

c. 1300, "the human face, a face; facial appearance or expression; likeness, image," from Old French face "face, countenance, look, appearance" (12c.), from Vulgar Latin *facia (source also of Italian faccia), from Latin facies "appearance, form, figure," and secondarily "visage, countenance," which probably is literally "form imposed on something" and related to facere "to make" (from PIE root *dhe- "to set, put").

Replaced Old English andwlita "face, countenance" (from root of wlitan "to see, look") and ansyn, ansien, the usual word (from the root of seon "see"). Words for "face" in Indo-European commonly are based on the notion of "appearance, look," and are mostly derivatives from verbs for "to see, look" (as with the Old English words, Greek prosopon, literally "toward-look," Lithuanian veidas, from root *weid- "to see," etc.). But in some cases, as here, the word for "face" means "form, shape." In French, the use of face for "front of the head" was given up 17c. and replaced by visage (older vis), from Latin visus "sight."

From late 14c. as "outward appearance (as contrasted to some other reality);" also from late 14c. as "forward part or front of anything;" also "surface (of the earth or sea), extent (of a city)." Typographical sense of "part of the type which forms the letter" is from 1680s.

Whan she cometh hoom, she raumpeth in my face And crieth 'false coward.' [Chaucer, "Monk's Tale"]

Face to face is from mid-14c. Face time is attested from 1990. To lose face "lose prestige" (1835), is from Chinese tu lien; hence also save face (1898; see save). To show (one's) face "make or put in an appearance" is from mid-14c. (shewen the face). To make a face "change the appearance of the face in disgust, mockery, etc." is from 1560s. Two faces under one hood as a figure of duplicity is attested from mid-15c.

Two fases in a hode is neuer to tryst. ["Awake lordes," 1460]

Middle English bok, from Old English boc "book, writing, written document," generally referred (despite phonetic difficulties) to Proto-Germanic *bōk(ō)-, from *bokiz "beech" (source also of German Buch "book" Buche "beech;" see beech), the notion being of beechwood tablets on which runes were inscribed; but it may be from the tree itself (people still carve initials in them).

Latin and Sanskrit also have words for "writing" that are based on tree names ("birch" and "ash," respectively). And compare French livre "book," from Latin librum, originally "the inner bark of trees" (see library).

The sense gradually narrowed by early Middle English to "a written work covering many pages fastened together and bound," also "a literary composition" in any form, of however many volumes. Later also "bound pages," whether written on or not. In 19c. it also could mean "a magazine;" in 20c., a telephone directory.

The use of books or written charters was introduced in Anglo-Saxon times by the ecclesiastics, as affording more permanent and satisfactory evidence of a grant or conveyance of land than the symbolical or actual delivery of possession before witnesses, which was the method then in vogue. [Century Dictionary] 

From c. 1200 as "a main subdivision of a larger work." The meaning "libretto of an opera" is from 1768. A betting book "record of bets made" is from 1812. The meaning "sum of criminal charges" is from 1926, hence slang phrase throw the book at (1932). Book of Life "the roll of those chosen for eternal life" is from mid-14c. Book of the month is from 1926. To do something by the book "according to the rules" is from 1590s.