Definition of "composure"

That all may see who hate us, how we seekPeace and composure […]

1667, John Milton, “Book VI”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, lines 559-560

It would be also of great Use to us to form our deliberate Judgments of Persons and Things in the calmest and serenest Hours of Life, when the Passions of Nature are all silent, and the Mind enjoys its most perfect Composure […]

1725, Isaac Watts, chapter 3, in Logick: Or, The Right Use of Reason in the Enquiry after Truth, […], 2nd edition, London: […] John Clark and Richard Hett, […], Emanuel Matthews, […], and Richard Ford, […], published 1726

“Did you want anything, ma’am?” I enquired, still preserving my external composure, in spite of her ghastly countenance and strange exaggerated manner.

1847 December, Ellis Bell [pseudonym; Emily Brontë], Wuthering Heights, volumes (please specify |volume=I or II), London: Thomas Cautley Newby, […]

He began to lose his composure, and made mistakes, his cards got mixed up, and his scoring was wild.

1894, Giacomo Casanova, chapter 16, in Arthur Machen, transl., The Memoirs of Jacques Casanova de Seingalt‎, volume 4, London: Elek Books, page 407

Montenegro's early composure was shaken by that set-back and a visibly buoyed Wales nearly added a second goal when Bale broke past two defenders and fired a long-range shot that Bozovic tipped over

2011 September 2, “Wales 2-1 Montenegro”, in BBC‎

[…] Signr Pietro […] had an admirable way both of composure [in music] and teaching.

1818, John Evelyn, Memoirs, edited by William Bray, London: Henry Colburn, 2nd edition, Volume I, entry for 10 March, 1685, p. 592

[…] from the various Composures and Combinations of these Corpusoles together, happen all the Varieties of the Bodies formed out of them […]

1695, John Woodward, An Essay toward a Natural History of the Earth and Terrestrial Bodies‎, London: Richard Wilkin, Part 5, p. 230

[…] his composure must be rare indeedWhom these things can not blemish […]

c. 1606–1607, William Shakespeare, “The Tragedie of Anthonie and Cleopatra”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene iv]

[…] their fraction is more our wish than their faction: but it was a strong composure a fool could disunite.

c. 1602, William Shakespeare, “The Tragedie of Troylus and Cressida”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iii]