Answer: KEN

AnswerCrossword Clue
KENBoy toy
KENComprehension
KENKnowledge range
KENTrivia whiz Jennings
KENDocumentarian Burns
KENJennings of game-show fame
KENMental perception
KENJennings who won on "Jeopardy!"
KEN"Coach Carter" coach Carter
KENIntellectual range
KENBaseball's Griffey Jr.
KENUnderstanding
KENBarbie's doll
KENBoy toy?
KENGriffey of baseball
KENScope
KEN"Jeopardy!" millionaire Jennings
KENBarbie's ex
KENHoward or Norton
KENNovelist Kesey
kenow
KENCognizance
KENBarbie's beau
KENBarbie's guy
KENWriter Follett
KENHe's a real doll
KENMale doll
KENOlin or Berry
KENActor Berry
KENBarbie's boyfriend
KENBarbie's friend
KENAuthor Kesey
KENJeopardy's Jennings
KENMattel doll who's been a doctor, beach bum, soda jerk, and once even a faaaaabulous dude called "Earring Magic"
KENPlastic figure surnamed Carson who was, at least once, styled as a doctor
KENHe's a doll
KENAuthor Follett
KENRange of knowledge
KENEither Griffey
KENWriter Kesey