linchpin for learners of EnglishPowered by COBUILD (lɪntʃpɪn) also lynchpin
Word forms: linchpins
If you refer to a person or thing as the linchpin of something, you mean that they are the most important person or thing involved in it. [+ of] ⇒ He's the lynchpin of our team and crucial to my long-term plans.
`Today we in Britain are the linchpin of the democratic world, the bridge which brings the two halves of freedom together.Dobbs, Michael THE TOUCH OF INNOCENTSShe's the linchpin of this part of the operation and if she doesn't like it she shouldn't have volunteered.Ross, Melville LOHENGRINShe was the linchpin , the person around whom all else revolved, yet she preferred anonymity.Stephanie Laurens ALL ABOUT LOVE