self-contradictory
adjectiveUK /ˌself kɒntrəˈdɪktəri/
US /ˌself kɑːntrəˈdɪktəri/
Saying or showing two things that cannot both be true at the same time.
His excuse was self-contradictory because he said he was home all day but also that he went to the store.
RELATED WORDS
OTHER MEANINGS
2. Containing two parts that cancel each other out, so the whole statement cannot be true.
The sentence 'I always lie' is self-contradictory.
3. Behaving in ways that go against what one claims to believe.
Her self-contradictory actions made it hard to trust her promises.
4. In logic, a statement that is false no matter what, because it asserts and denies the same thing.
The formula 'P and not P' is self-contradictory.