kingpin

from WordNet (r) 3.0 (2006)
kingpin
    n 1: the most important person in a group or undertaking [syn:
         {kingpin}, {top banana}, {bigwig}]
    2: bolt that provides a steering joint in a motor vehicle [syn:
       {kingbolt}, {kingpin}, {swivel pin}]
    3: the front bowling pin in the triangular arrangement of ten
       pins [syn: {headpin}, {kingpin}]
    

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