The term 'in no uncertain terms' is an expression used to emphasize that something is being said with absolute certainty and clarity. The two crossword solutions for this term are 'CLEARLY' (7 letters) and 'flatly' (6 letters). Both words can be used to describe the certainty of a statement, with 'CLEARLY' suggesting that the statement is easily understood and 'flatly' suggesting that the statement is stated without any emotion or hesitation.