from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To harden the surface or case of (iron or steel) by high-temperature shallow infusion of carbon followed by quenching.
- transitive v. To make callous or insensitive.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To harden the surface of iron or steel by infusing carbon into the surface layer
- v. To make insensitive to hardship
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To subject to a process which converts the surface of iron into steel.
- transitive v. To render insensible to good influences.
from The Century Dictionary and Cyclopedia
- To harden the outer part or surface of, as anything made of iron, by converting the iron into steel.
Sorry, no etymologies found.
A Uberti in 44-40 Blue/caseharden Steel, NM, 5 l/2 bbl, Walnut grips.
I am persuaded that all valetudinarians are too sedentary, too regular, and too cautious — We should sometimes increase the motion of the machine, to unclog the wheels of life; and now and then take a plunge amidst the waves of excess, in order to caseharden the constitution.
The same salt may be used to caseharden wrought iron.