inveteracy

[ in-vet-er-uh-see ]

/ ɪnˈvɛt ər ə si /

the quality or state of being inveterate or deeply ingrained: the inveteracy of people's prejudices.

Origin of inveteracy

First recorded in 1710–20; inveter(ate) + -acy

Now see with what earnestness and inveteracy the friends of the Colonization Society oppose immediate abolition!

Thoughts on African Colonization |William Lloyd Garrison
The impudence, the inveteracy of that fellow, is astonishing—no silencing him.

Tales And Novels, Volume 8 (of 10) |Maria Edgeworth
Thus chorea may sometimes reach a degree of inveteracy that renders sleep impossible.

Insomnia; and Other Disorders of Sleep |Henry M. Lyman
It really does seem to me a kind of inveteracy thus to talk of buying a new yacht within a few hours after losing one.

Roland Cashel |Charles James Lever

“The New Yorkers never forgave him,” says your latest biographer; and one scarcely marvels at the inveteracy of their malice.

Letters to Dead Authors |Andrew Lang