Gainsay
Part of speech: verb
Definition: To contradict; to deny; to controvert; to dispute; to forbid.
Challenge
Part of speech: noun
Definition: An instigation or antagonization intended to convince a person to perform an action they otherwise would not.A difficult task, especially one that the person making the attempt finds more enjoyable because of that difficulty.A judge's interest in the result of the case for which he or she should not be allowed to sit the case, e.g. a conflict of interest.
Part of speech: verb
Definition: To invite someone to take part in a competition.To dare someone.To dispute something.To make a formal objection to a juror.
Example sentence: Synergy is what happens when one plus one equals ten or a hundred or even a thousand! It's the profound result when two or more respectful human beings determine to go beyond their preconceived ideas to meet a great challenge.