In No Uncertain Terms Meaning

(idiomatic) (with subject-verb inversion, this takes on a negative meaning)

Example: 1919, Stewart Edward White, The Killer, ch. 11,
  The latter held up the lamp where it wouldn't get smashed and admonished them in no uncertain terms that he wanted me alive.
1961, "Toughening Up", Time, 3 Nov.,
  Kennedy assured West German Ambassador Wilhelm Grewe in no uncertain terms that he does not intend to let West Berlin go down the drain.
2011, Ben McGrath, "Does football have a future: The NFL and the concussion crisis", The New Yorker, 31 Jan.,
  In no uncertain terms do I believe that we should outlaw or 'wuss down' contact sports!!!