vi to become confirmed or strengthened, in either a good or a bad sense.
2. harden ·vi to become hard or harder; to acquire solidity, or more compactness; as, mortar hardens by drying.
3. harden ·vt to make hard or harder; to make firm or compact; to indurate; as, to harden clay or iron.
4. harden ·vt 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.