Etymology
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composure (n.)

c. 1600, "composition, act of composing, constructing, arrangement" (also, in early use, with many senses now given to compound (n.2)), from compose + -ure. Sense of "tranquility, calmness, composed state of mind" is first recorded 1660s, from composed "calm" (c. 1600). For sense, compare colloquial fall apart "lose one's composure."

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cool (n.)

c. 1400, "moderate state of cold, coolness," from cool (adj.). Meaning "one's self-control, composure" (the thing you either keep or lose) is from 1966.

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kitten (n.)

late 14c., kitoun, "the young of a domesticated cat," probably from an Anglo-French variant of Old French chaton, chitoun (Old North French caton) "little cat," a diminutive of chat "cat," from Late Latin cattus (see cat (n.)). In playful use, "a young girl, a sweetheart," from 1870. As a verb, "bring forth kittens," late 15c. To have kittens "lose one's composure" is from 1908.

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abash (v.)

"perplex or embarrass by suddenly exciting the conscience, discomfit, make ashamed," late 14c., earlier "lose one's composure, be upset" (early 14c.), from Old French esbaiss-, present stem of esbaer "lose one's composure, be startled, be stunned."

Originally, to put to confusion from any strong emotion, whether of fear, of wonder, shame, or admiration, but restricted in modern times to effect of shame. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]

The first element is es "out" (from Latin ex; see ex-). The second may be ba(y)er "to be open, gape" (if the notion is "gaping with astonishment"), possibly ultimately imitative of opening the lips. Middle English Compendium also compares Old French abaissier "bow, diminish, lower oneself" (source of abase). Related: Abashed; abashing. Bashful is a 16c. derivative.

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sang-froid (n.)

also sangfroid, "presence of mind, coolness, mental composure," 1712, from French sang froid, literally "cool blood," from sang "blood" (from Latin sanguis; see sanguinary) + froid "cold" (from Latin frigidus; see frigid). "In the 17th c. the expression was in France often written erroneously sens froid, as if it contained sens "sense" instead of the homophonous sang "blood'." [OED].

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constance (n.)

obsolete form of constancy, mid-14c., constaunce, "steadfastness, self-possession, composure," from Old French constance "steadfastness, permanence" (14c.), from Latin constantia "firm standing, steadiness, firmness, unchangeableness; firmness of character" (source of Italian costanza, Spanish constancia), abstract noun from present-participle stem of constare "to stand together" (see constant (adj.)). Obsolete since 17c. except as a given name for a girl (familiarly Connie), in which use it enjoyed a mild popularity in U.S. c. 1945-1955.

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recharge (v.)

early 15c., "to reload" (a vessel), from re- "again, back" + charge (v.) "to load" (q.v.); modeled on Old French rechargier "to load, load back on" (13c.). The general sense of "put a fresh charge in, reload, refill" is by 1839 and might be a new formation from the same elements. The meaning "re-power" a battery is from 1876, hence the figurative senses of "restore fitness, refresh mental composure" (by 1921). Related: Recharged; recharging. The noun is recorded from 1610s in English, "a fresh charge or load."

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err (v.)
c. 1300, from Old French errer "go astray, lose one's way; make a mistake; transgress," from Latin errare "wander, go astray," figuratively "be in error," from PIE root *ers- (1) "be in motion, wander around" (source also of Sanskrit arsati "flows;" Old English ierre "angry; straying;" Old Frisian ire "angry;" Old High German irri "angry," irron "astray;" Gothic airziþa "error; deception;" the Germanic words reflecting the notion of anger as a "straying" from normal composure). Related: Erred; erring.
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countenance (n.)

mid-13c., contenaunce, "behavior, bearing, conduct, manners;" early 14c., "outward appearance, looks," from Old French contenance "demeanor, bearing, conduct," from Latin continentia "restraint, abstemiousness, moderation," literally "way one contains oneself," from continentem, present participle of continere "to hold together, enclose," from assimilated form of com "with, together" (see con-) + tenere "to hold," from PIE root *ten- "to stretch."

The meaning evolved in late Middle English from "appearance" to "facial expression betraying or expressing a state of mind," to "the face" itself. Hence also, figuratively, "aspect imparted to anything."

Also formerly "controlled behavior, self-control, composure" (c. 1300); in Chaucer to catch (one's) contenaunce is to gain self-control. In later Middle English it also could mean "outward show, pretense."

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poise (n.)

early 15c., pois, "weight, quality of being heavy," later "significance, importance" (mid-15c.), from Old French pois "weight, balance, consideration" (12c., Modern French poids, with -d- added 16c. on supposed derivation from Latin pondus "weight"), from Medieval Latin pesum "weight," from Latin pensum "something weighted or weighed," (source of Provençal and Catalan pes, Spanish, Portuguese, Italian peso), noun use of neuter past participle of pendere "to hang, cause to hang; weigh" (from PIE root *(s)pen- "to draw, stretch, spin").

Original senses are obsolete. The figurative sense (in reference to abstract things) of "steadiness, balance, equilibrium, composure" is recorded from 1640s, from the sense of "a state of of being equally weighted on either side" (1550s). The meaning "way in which the body is carried" is from 1770.

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