inure

inure \in-YOOR\, transitive verb:

1. To make accustomed or used to something painful, difficult, or inconvenient; to harden; to habituate; as, "inured to drudgery and distress.

intransitive verb:
1. To pass into use; to take or have effect; to be applied; to serve to the use or benefit of; as, a gift of lands inures to the heirs.

They were a hard-driven, hardworking crowd inured to the hardest living, and they found their recreation in hard drinking and hard fighting.
-- Allen Barra, Inventing Wyatt Earp

How does one become inured to unpredictable moments of helplessness?
-- Stephen Kuusisto, Planet Of The Blind

At school, he repeatedly jabbed the nib of his pen into his hand, wanting to inure himself to agony.
-- Peter Conrad, "Enter the philosopher, with an axe", The Observer, September 8, 2002

Inure derives from prefix in-, "in" + obsolete ure, "use, work," from Old French uevre, "work," from Latin opera, "trouble, pains, exertion," from opus, "work."