Meaning of HARDEN in English

HARDEN

hard ‧ en /ˈhɑːdn $ ˈhɑːrdn/ BrE AmE verb [intransitive and transitive]

[ Word Family: noun : ↑ hardship , ↑ hardness , ↑ hardiness ; adjective : ↑ hard , ↑ hardened , ↑ hardy ; adverb : ↑ hard , ↑ hardly ; verb : ↑ harden ]

1 . to become firm or stiff, or to make something firm or stiff OPP soften :

It will take about 24 hours for the glue to harden.

2 . if your attitude hardens, or if something hardens it, you become more strict and determined and less sympathetic OPP soften :

Attitudes towards the terrorists have hardened even more since the attack.

3 . written if your face or voice hardens, or if something hardens it, you look or sound less sympathetic or happy OPP soften :

His face hardened momentarily, then he looked away.

4 . harden your heart to make yourself not feel pity or sympathy for someone

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.