1580s, "warehouse, place for storing goods, especially military ammunition," from French magasin "warehouse, depot, store" (15c.), from Italian magazzino, from Arabic makhazin, plural of makhzan "storehouse" (source of Spanish almacén "warehouse, magazine"), from khazana "to store up." The original sense is almost obsolete. Meaning "cartridge chamber in a repeating rifle" is by 1868; that of "a case in which a supply of cartridges is carried" is by 1892.
The meaning "periodical journal containing miscellaneous writings" dates from the publication of the first one, Gentleman's Magazine, in 1731, which was so called from earlier use of the word for printed lists of military stores and information, or in a figurative sense, from the publication being a "storehouse" of information (originally of books, 1630s).
1887, "to cover with a network," from network (n.). From 1940 as "to broadcast over a (radio) network;" 1972 in reference to computers; by 1982 in reference to persons, "to interact with others to exchange information and develop contacts." Related: Networked; networking.
1979 as an abbreviation of compact disc as a digital system of information storage. By 1959 as an abbreviation of certificate of deposit "written statement from a bank acknowledging it has received a sum of money from the person named" (1819).
1828, "arranged in classes," past-participle adjective from classify. Meaning "secret" (in reference to government information) is from 1941, American English. Classifieds (n.) "newspaper advertisements arranged by classes," 1913, is short for classified advertisements
early 15c., "readiness" (in phrase in prompte), from Latin promptus (see prompt (v.)). Meaning "hint, information suggested, act of prompting" is from 1590s. The computer sense of "message given by a computer requiring or helping the user to respond" is by 1977.
"publisher's inscription at the end of a book," 1774, from Late Latin colophon, from Greek kolophōn "summit, final touch" (from PIE root *kel- (2) "to be prominent; hill"). "In early times the colophon gave the information now given on the title page" [OED].