transitive verb Date: 1677 to harden (a ferrous alloy) so that the surface layer is harder than the interior, to make callous or insensible, ~ed adjective
CASE-HARDEN
Meaning of CASE-HARDEN in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012