"innumerable, countless," 1570s, from number (n.) + -less.

phonetic coding system, 1959, from sound (n.1) + brand-name suffix -ex.

1841, "to spread a system of principles," from propaganda + -ize. Related: Propagandized; propagandizing.

by 1717, in algebra textbooks, in phrase to the nth, a mathematical term indicating an indefinite number, in which n is an abbreviation for (whole) number (n.). Figurative (non-mathematical) use is by 1852.

Old English clyster "a number of things growing naturally together," probably from the same root as clot (n.). Meaning "a number of persons, animals, or things gathered in a close body" is from c. 1400. Of stars, from 1727. Cluster-bomb attested by 1950.

"act or process of reducing to a code or system," 1817 (Bentham), noun of action from codify.

"alteration from one system to another," 1907, from the verbal phrase; see change (v.) + over (adv.).

"made shut, not open," c. 1200, past-participle adjective from close (v.). Closed circuit "complete, unbroken (electrical) circuit" is attested from 1827; closed shop"workplace in which only union members are employed" is from 1904; closed system first recorded 1896 in William James as "complete and unalterable system (of doctrines, etc.)." Later used in a physical sense, "system in which the total mass or energy remains constant."