contradict
/ˌkɑːntrəˈdɪkt/
verb
-dicts; -dicted; -dicting
[+ obj] to say the opposite of (something that someone else has said) :to deny the truth of (something)
to deny or disagree with what is being said by (someone)
to not agree with (something) in a way that shows or suggests that it is false, wrong, etc.
contradict yourself
to say or do something that is opposite or very different in meaning to something else that you said or did earlier