(1)(使)变硬(坚强，强壮)((cause sth or oneself to) become hard， firm or stiff，stronger and more able to deal with difficulty)[I，T+n]：The snow/chocolate/glue～ed. 雪/巧克力/胶水变硬了。His mind～ed.他的心肠硬了起来。The opposition to the military government～s. 对军政府的反抗强硬起来。～in one's resolve 坚定了自己的决心;～the defences加强防御;～the steel/the clay使钢/泥土变硬;～one's body/one's heart使身体强壮/心肠硬起来;～hold on the door更紧地抓住门;～sb considerably 使某人坚强了许多;

(2)使变得冷酷(麻木)(make sb less sensitive to sth)[尤pass：T+n，T+n+prep (to)]：be/become～ed to failure/the sight of blood/the suffering around oneself 对失败/见到血/周围人的痛苦变得无动于衷;a～ed criminal 死不改悔的罪犯;

【用法】harden只用于表示“坚硬，坚强”或“严酷，苛刻”，例如：leave the wet cement to harden(让湿的水泥硬起来);She hardened her heart.(她硬起心肠来。)在其他场合用get hard(er)，例如：The exercises in this book gradually get harder.(这本书的练习逐渐变难。)Life is getting hard for people on low incomes.(低收入者的生活变得艰难起来。)