LEARNit Dictionary
linchpin
noun
/ˈlɪntʃpɪn/
UK
/ˈlɪntʃpɪn/
US
1
a person or thing that is the most important part of an organization, a plan, etc., because everything else depends on them or it
محور اصلی, رکن اساسی, عنصر حیاتی, فرد کلیدی