1560s, "single number regarded as an undivided whole," alteration of unity on the basis of digit. Popularized in John Dee's English translation of Euclid, to express Greek monas (Dee says unity formerly was used in this sense). Meaning "single thing regarded as a member of a group" is attested from 1640s. Extended sense of "a quantity adopted as a standard of measure" is from 1738. Sense of "group of wards in a hospital" is attested from 1893.
late 14c., "roll of parchment containing writing; a bound book," from Old French volume "scroll, book; work, volume; girth, size" (13c.) and directly from Latin volumen (genitive voluminis) "roll (of a manuscript); coil, wreath," literally "that which is rolled," from volvere "to turn around, roll," from PIE root *wel- (3) "to turn, revolve." Meaning "book forming part of a set" is 1520s in English, from that sense in French. Generalized sense of "bulk, mass, quantity" (1620s) developed from that of "bulk or size of a book" (1520s), again following the sense evolution in the French word.
unit of the metric system for solid measure, 1798, from French stère "unit of volume equal to one cubic meter," from Greek stereos "solid, stiff, firm" (from PIE root *ster- (1) "stiff"). Little used, cubic meter generally serving instead.
1510s, "a single volume of a multi-volume work," from French tome (16c.) or directly from Latin tomus "section of a book, tome," from Greek tomos "volume, section of a book," originally "a section, piece cut off," from temnein "to cut," from PIE root *tem- "to cut." Sense of "a large book" is attested from 1570s.
1610s, "forming a large mass," also "full of turnings and windings," from Late Latin voluminosus, from Latin volumen (genitive voluminis) "volume" (see volume). Related: Voluminously; voluminousness.
1854, from volumeter "instrument for measuring the volume of liquids and gases" (1827) + -ic. Related: Volumetrical (1853).
"manuscript volume (especially an ancient one)," 1845, from Latin codex "book" (see code (n.)). Related: Codical.
1610s, "unity, arithmetical unit," 1610s, from Late Latin monas (genitive monadis), from Greek monas "unit," from monos "alone" (from PIE root *men- (4) "small, isolated"). In Leibnitz's philosophy, "an ultimate unit of being, a unit of the universal substance" (1748); he apparently adopted the word from Giordano Bruno's 16c. metaphysics, where it referred to a hypothetical primary indivisible substance at once material and spiritual. Related: Monadic; monadism.