inveterate

Etymology

From Latin inveteratus (“of long standing, chronic”), form of inveterare, from in- (“in, into”) + veterare (“to age”), from vetus, form of veteris (“old”); latter ancestor to veteran. Cognate to Italian inveterato.

adj

1. firmly established from having been around for a long time; of long standing
   an inveterate disease
   an inveterate habit
   In Montpelier, where this prison stands, the inveterate prejudice against prisoners has been swept away. 1911, Morrison I. Swift, “Humanizing the Prisons,”, in The Atlantic
2. (of a person) Having had a habit for a long time
   an inveterate idler
   an inveterate smoker
   an inveterate traveller
   Like many lonely people, he was an inveterate hoarder, making and surrounding himself with objects, barriers against the demands of human intimacy. 2017, Olivia Laing, The Lonely City: Adventures in the Art of Being Alone, New York: Picador, page 6
3. Malignant; virulent; spiteful.
   A man of mild manners can form no idea of inveterate revenge or cruelty[…] 1748, David Hume, Enquiries concerning the human understanding and concerning the principles of morals, London: Oxford University Press, published 1973, § 15
   1765–70, Henry Brooke, The Fool of Quality; or, The History of Henry, Earl of Moreland This his lordship perused with a countenance, and scrutiny, apparently inveterate.

verb

1. (obsolete) To fix and settle after a long time; to entrench.
   "the vulgar conceived that now there was an end given, and a consummation to superstitious prophecies, the belief of fools, but the talk sometimes of wise men, and to an ancient tacit expectation which had by tradition been infused and inveterated into men's minds." 1622, Francis Bacon, The History of the Raigne of King Henry the Seventh
   "none of these Princes do use to maintaine any armies together, which are annex'd and inveterated with the governments of the provinces, as were the armies of the Roman Empire. " 1640, Edward Dacres, translation of The Prince by Niccolò Machiavelli, Chapter XIX http://www.gutenberg.org/etext/15772
   The foregoing elements of disunion are inveterated by the constituent formation of our national legislature. In the French chambers the members are all Frenchmen ; but our members of Congress are effectively Georgians, New-Yorkers, Carolinians, Pennsylvanians, &c. 1851 January, author unknown, "The Philosophy of the American Union, in The United States Magazine and Democratic Review, page 16