IPA: /ˈkɪŋˌpɪn/
KK: /ˈkɪŋˌpɪn/
The most important person or element in a group or organization, often playing a central role in its operations.
He was considered the kingpin of the local business community, influencing many decisions.
Kingpin → It is formed from "king" (from Old English "cyning", meaning ruler or sovereign) and "pin" (from Middle English "pin", meaning a small cylindrical object used to hold things together). The term "kingpin" originally referred to the most important or central person in a group or organization, akin to the main pin that holds everything together.
Think of a 'ruler' ('king') who is the most important part ('pin') of a group, helping you remember that a kingpin is the central figure in a situation.
No commonly confused words.