harden Definition

harden
verb hardened, hardening

tr & intr
1. To make or become hard or harder.

Thesaurus: solidify, crystallize, bake, cement, consolidate, concentrate, fossilize, freeze, ossify, petrify, vitrify, vulcanize; Antonym: soften, melt.
tr & intr
2. To become or make less sympathetic or understanding.

Example: He hardened his heart to her tears
3. To make or become stronger or firmer.

Thesaurus: brace, buttress, fortify, gird, reinforce, toughen, acclimate, accustom, habituate, inure, season, indurate, develop, nerve; Antonym: weaken, debilitate.
intr
4a. commerce.
Said of prices, a market, etc: to stop fluctuating;
intr
4b. commerce.
Said of prices: to rise.

Derivative: hardened

Rigidly set, eg in a behavioural pattern.

Toughened through experience and not likely to change.
Example: a hardened criminal

Derivative: hardener
noun

Phrasal Verb: harden something off

To accustom (a plant) to cold, frost, etc by gradually exposing it to outdoor conditions.