顶梁柱
【注音】dǐng liáng zhù
【解释】起主要作用的骨干或核心人物。
This is a metaphor for people who play the principal role of a backbone or the key figure.
【例子】
例：小舟虽然没上过大学，但他自己刻苦学习，成了厂里的技术骨干，大家说在业务上他是顶梁柱。
Ex.：Xiao Zhou hasn’t been to college, but he studied assiduously by himself and became the backbone technician of the factory, or the key figure in profession, as everyone says.