sinew
noun uk/ˈsɪn.juː/ us/ˈsɪn.juː/
[ C ]腱，筋肉
a tendon (= strong piece of tissue in the body connecting a muscle to a bone)
[ C usually plural ]支架，支柱
a part of a structure or system that provides support and holds it together
These steel posts form the sinews of the building. 这些钢柱构成了该大楼的骨架。
Idiom
sinews of waridiom literary 战争原动力（战争过程中用于购买武器和补给的资金）
the money needed for weapons and supplies during a war