early 15c., "pertaining to sclerosis," from medical Latin scleroticus, from Greek skleroun (see sclerosis). Figurative meaning "unchanging, rigid" is from 1961.
early 15c., "unchanging, unalterable," from Old French immutable (Modern French immuable), and directly from Latin immutabilis "unchangeable, unalterable," from assimilated form of in- "not, opposite of" (see in- (1)) + mutabilis "changeable," from mutare "to change" (from PIE root *mei- (1) "to change, go, move"). Related: Immutably.
"eternal and unchanging, perpetual, everlasting, having no end," early 15c., from Old French sempiternel "eternal, everlasting" (13c.) or directly from Medieval Latin sempiternalis, from Latin sempiternus "everlasting, perpetual, continual," from semper "always, ever" (see semper-). Compare aeternus from aevum (for which see eternal). Related: Sempiternally; sempiternity. The earlier Middle English adjective was sempitern (late 14c.) from Old French sempiterne and Latin sempiternus.
Trawthe is immortalle, immutable, and sempiternalle.
[Higden's "Polychronicon," 15c. translation]
13th letter of the English alphabet, from Greek mu, from Semitic mem. It represents a very stable and unchanging sound in Indo-European, described by Johnson as "a kind of humming inward." The Roman symbol for 1,000; sometimes used in this sense in English 15c.-16c.; but in late 20c. newspaper headlines it stands for million. As a thickness of type, from 1680s (commonly spelled out, em).
c. 1300, "custom, habit," in phrase bi rote "by heart," a word of unknown origin, sometimes said to be connected with Old French rote "route" (see route (n.)), or from Latin rota "wheel" (see rotary), but OED calls both suggestions groundless. Meaning "a fixed or unchanging round," as in learning or reciting, is by 1580s. As a verb, "repeat, say from memory," 1590s.
mid-12c., "trustworthy, reliable;" mid-13c., "constant, steadfast; virtuous;" from Old French stable, estable "constant, steadfast, unchanging," from Latin stabilis "firm, steadfast, stable, fixed," figuratively "durable, unwavering," literally "able to stand," from PIE *stedhli-, suffixed form of root *sta- "to stand, make or be firm." From c. 1300 as "well-founded, well-established, secure" (of governments, etc.). Physical sense of "secure against falling" is recorded from late 14c.; also "of even temperament." Of nuclear isotopes, from 1904.
"enduring, unchanging, unchanged, lasting or intended to last indefinitely," early 15c., from Old French permanent, parmanent (14c.) or directly from Latin permanentem (nominative permanens) "remaining," present participle of permanere "endure, hold out, continue, stay to the end," from per "through" (from PIE root *per- (1) "forward," hence "through") + manere "stay" (from PIE root *men- (3) "to remain").
Related: Permanently. As a noun meaning "permanent wave," by 1909. Of clothing, permanent press, in reference to a process designed to produce lasting creases in fabric," is attested from 1964.
