strengthen
/ˈstreŋθn; `strɛŋθən/ v[I, Tn]
(cause sth/sb to) become stronger （使某物[某人]）更强
The currentstrengthened as we moved down the river. 我们顺流而下时, 水流更急了.
a special shampoo to strengthen your hair 能保养头发的一种特效洗发剂
strengthen a garrison with extra troops 增派部队以加强驻地的兵力
This latest development has further strengthened my determination to leave. 最近事态的发展更增强了我离开的决心.