1796, in secular sense, "caste custom, right behavior;" in Buddhism and Hinduism, "moral law," from Sanskrit, "statute, law; right, justice," etymologically "that which is established firmly," from PIE root *dher- "to hold firmly, support." Compare cognate Latin firmus "strong; stable," figuratively "constant, trusty."
late 14c., "able to turn, revolving;" early 15c., "liable to constant change," from Latin volubilis "that turns around, rolling, flowing," figuratively (of speech) "fluent, rapid," from volvere "to turn around, roll" (from PIE root *wel- (3) "to turn, revolve"). Meaning "fluent, talkative" is recorded from 1580s. Related: Volubly.
1520s, of uncertain origin, perhaps an alteration of French tremouille "mill hopper," in reference to the hopper's constant motion to and fro, from Latin trimodia "vessel containing three modii," from modius, a Roman dry measure, related to modus "measure." Attested earlier in English as a verb (1510s), though this now is obsolete.
Self-government begins with a reverential recognition of a supreme law: its process is a constant endeavor to render that law objective, real, operative—to externalize it, if we may use the term. [American Review, July, 1846]
1768, a type of optical instrument or telescope, from Greek pan "all" (see pan-) + optikon, neuter of optikos "of or for sight" (from PIE root *okw- "to see"). Later it was also the name of a type of prison designed by Bentham (1791) in which wardens had a constant view of all inmates, and "a showroom" (1850).
Greek letter corresponding to the Roman P, from Phoenician, literally "little mouth." As the name of the mathematical constant for the ratio of the circumference of a circle to the diameter, from 1841 in English, used in Latin 1748 by Swiss mathematician Leonhard Euler (1707-1783), as an abbreviation of Greek periphereia "periphery." For the printer's term for mixed type (often spelled pi), see pie (3).
late 14c., "weak, unsound" (of things), from Latin infirmus "weak, frail, feeble, not strong or firm" (figuratively "superstitious, pusillanimous, inconstant"), from in- "not, opposite of" (see in- (1)) + firmus "strong; stable," figuratively "constant, trusty" (from suffixed form of PIE root *dher- "to hold firmly, support" ). Of persons, "not strong, unhealthy," first recorded c. 1600. As a noun from 1711.
late 14c., ferm, "strong, steady" (of things), "permanent, enduring" (of agreements), "steadfast, steady" (of persons), "sound, well-founded" (of arguments), from Old French ferm "strong, vigorous; healthy, sound; steadfast, loyal, faithful" (12c.), from Latin firmus "strong, steadfast, enduring, stable," figuratively "constant, steadfast, trusty, faithful," from suffixed form of PIE root *dher- "to hold firmly, support." The spelling return to -i- in late 1500s was modeled on Latin. Related: Firmly; firmness.
"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."