Answer: thelastword

AnswerCrossword Clue
THELASTWORDUltimate authority.
THELASTWORDLatest style: Slang.
THELASTWORDReigning fad
THELASTWORDLatest, most modern thing
THELASTWORDEnd of the quip
THELASTWORDEnd of the truism
THELASTWORDEnd of a solver's thought
THELASTWORDFinal remark in an argument