harden-v; 2 Senses

Sense Number 1: (Cause to) become physically or metaphorcally harder.

Commentary: Syntax Includes: NP1[agent] HARDEN NP2[patient[inanimate]] NP1[topic[inanimate] HARDEN

After one too many disappointments, John hardened his heart.
The cold hardened the butter.
The factory hardens steel.

VerbNet: other_cos-45.4
FrameNet: Change_of_consistency,Cause_change_of_consistency
PropBank: harden.01
WordNet 3.0 Sense Numbers: 1, 2, 3

Sense Number 2: (Cause to) become fit or habituate to.

Commentary: Syntax Includes: NP1[agent] HARDEN NP2[patient[animate]]
NOTE: Action may be reflexive.

This trip will harden even the most experienced traveller.
He hardened himself over weeks in the mountains.
These emotional trials have hardened me.

VerbNet: NM
FrameNet: NM
PropBank: NM
WordNet 3.0 Sense Numbers: 4, 5