stiffened

v.使 ... 坚硬；变为浓粘；使坚定；使强硬

This lignification serves to stiffen and strengthen the cells. 木质化足以使细胞变硬和增强。

This sort of grease could not stiffen when the temprature drops. 温度下降时，这种润滑脂不会变稠。

He stiffened at the insult. 他听到这些侮辱的话，态度强硬起来。