1. to make demands more strict, rigid, or difficult to meet; to become more adamant or uncompromising in one's requirements
The union decided to harden demands for better working conditions.
O sindicato decidiu enrijecer as exigências por melhores condições de trabalho.
2. to increase the severity or intensity of requirements or conditions
Management hardened demands after the failed negotiations.
A administração endureceu as exigências após as negociações fracassadas.