contradict
/ˌkɒntrəˈdɪkt/·컨트러딕트·verb
to say the opposite; to be inconsistent with
LatinCEFR B2
Root
contra- (against) + Latin 'dicere' (to say)
Latin contradicere (speak against) → Middle English contradicten
In a word
contra- (against) + dict (say) = 'speak from the opposite side'. You contradict an opponent in debate, and your actions can contradict your own words. Whether it comes from mouth or hand, the heart of the root is the same: two different "sayings" coming from one source.
Examples
Don't contradict your teacher in public.
His actions contradict his words.
The new data contradicts the earlier report.
Related
predictdictateverdictcontradictiondictionary