Definition of "complacency"

Others proclaim the infirmities of a great man with satisfaction and complacency, if they discover none of the like in themselves.

1712 January 4 (Gregorian calendar), [Joseph Addison; Richard Steele et al.], “MONDAY, December 24, 1711”, in The Spectator, number 256; republished in Alexander Chalmers, editor, The Spectator; a New Edition, […], volume III, New York, N.Y.: D[aniel] Appleton & Company, 1853

[…] looking at Mr. George Osborne's pale interesting countenance, and those beautiful black, curling, shining whiskers, which the young gentleman himself regarded with no ordinary complacency, she thought in her little heart that in His Majesty's army, or in the wide world, there never was such a face or such a hero.

1847 January – 1848 July, William Makepeace Thackeray, chapter 5, in Vanity Fair […], London: Bradbury and Evans […], published 1848

There was something pathetic in his concentration as if his complacency, more acute than of old, was not enough to him any more. When, almost immediately, the telephone rang inside and the butler left the porch Daisy seized upon the momentary interruption and leaned toward me.

1925, F[rancis] Scott Fitzgerald, chapter 1, in The Great Gatsby, New York, N.Y.: Charles Scribner’s Sons, published 1953