Is “Kingpin” a Scrabble word?
Yes
KINGPIN
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Kingpin
/ˈkɪŋ.pɪn/
noun
1.(motorized vehicles) The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt.
2.The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.
3.The most important person in an undertaking or organization.
Synonyms: big cheese, big enchilada, big kahuna, big noise, big tamale, big wheel