• Webster's Revised Unabridged Dictionary
    • Casehardened Hardened against, or insusceptible to, good influences; rendered callous by persistence in wrongdoing or resistance of good influences; -- said of persons.
    • Casehardened Having the surface hardened, as iron tools.
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Century Dictionary and Cyclopedia
    • casehardened Having the outside hardened, as iron tools, etc.
    • casehardened Figuratively, not sensitive; having no sense of shame; indifferent to reproof or dishonor.
    • ***


In literature:

The same salt may be used to caseharden wrought iron.
"Scientific American Supplement, No. 430, March 29, 1884" by Various
Many of the parts are of cast iron, rendered malleable by annealing, and finally casehardened.
"Scientific American Supplement, No. 598, June 18, 1887" by Various
Pack the pieces to be casehardened in the iron box so as not to touch each other or the box.
"Burroughs' Encyclopaedia of Astounding Facts and Useful Information, 1889" by Barkham Burroughs
But I must take exercise, and caseharden myself.
"The Journal of Sir Walter Scott" by Walter Scott
A casehardened lawyer like myself would do that.
"Lippincott's Magazine, November 1885" by Various
Nowhere else have I seen rocks casehardened with primal mud.
"Under the Maples" by John Burroughs
I have a peculiar kind of steel which I cannot harden by fire and water, neither will it caseharden by prussiate of potash.
"Scientific American, Vol. XXXIX.--No. 24. [New Series.], December 14, 1878" by Various