Webster’s Revised Unabridged Dictionary · 1913
Harden
Hard′en (härd′'n), v. t. [imp. & p. p. Hardened (-'nd); p. pr. & vb. n. Hardening (-'n·ĭng).] [OE. hardnen, hardenen.] 1. To make hard or harder; to make firm or compact; to indurate; as, to harden clay or iron.
2. To accustom by labor or suffering to endure with constancy; to strengthen; to stiffen; to inure; also, to confirm in wickedness or shame; to make unimpressionable. "Harden not your heart." Ps. xcv. 8.
I would harden myself in sorrow. Job vi. 10.
Hard′en, v. i. 1. To become hard or harder; to acquire solidity, or more compactness; as, mortar hardens by drying.
The deliberate judgment of those who knew him [A. Lincoln] has hardened into tradition. The Century.
2. To become confirmed or strengthened, in either a good or a bad sense.
They, hardened more by what might most reclaim. Milton.