self-contradictory
🇺🇸
/ˌself kɑːntrəˈdɪktəri/
🇬🇧
/ˌself kɒntrəˈdɪktəri/
Something that has two parts that cannot both be true at the same time.
His argument was self-contradictory, making it hard to believe him.
彼の議論は自己矛盾的で、彼を信じることが難しくなってしまった。