(intransitive) To become hard (tough, resistant to pressure). || (transitive, ergative) To make something hard or harder (tough, resistant to pressure). || (computing) To modify (a website or other system) to make it resistant to malicious attacks. || (transitive, dated) To become or make (a person or thing) resistant or less sensitive. || (phonology) To become or make (a consonant) more fortis.
Indigenous people of those areas were the first to notice that the liquid would gradually harden and turn black on exposure to air.
Of course, she would read what he had written, and in his words find that which would harden her against the trials to come.
She juggled three jobs to pay for an overseas adventure that would harden her to the battles she would later have in business.
例句
HMW-GS Compositions and Genetic Diversities of Wheat Cultivars (Lines)with Different Hardnesses
不同硬度类型小麦高分子量谷蛋白亚基组成及遗传多样性分析
属类：行业术语-中文论文标题--
Available in two hardnesses , 60 Shore A and 75 Shore A, Santoprene TPE 291-60B150 and 291-75B150 retain full bond strength in various environments including hot air, oil and aqueous solutions.
词性:|noun|
‘people complained about the _hardness_ of the chairs’
