- challenge: take exception to; "She challenged his claims"
- In classical logic, a contradiction consists of a logical incompatibility between two or more propositions. It occurs when the propositions, taken together, yield two conclusions which form the logical, usually opposite inversions of each other. ...
- To contradict; to deny, refute; to controvert; to dispute; to forbid
- (gainsaying) Opposition, especially in speech; Refusal to accept or believe something; Contradiction; Denial; denying; Rebellious opposition; rebellion
- (v) - to speak against, to oppose, to deny
- I still confuse "gainsay" and "vouchsafe" because they have the same emotional tone.