自打嘴巴 (zi6 daa2 zeoi2 baa1) — slap one's own face in Cantonese
ziˍ₆自daaˊ²打zeoiˊ²嘴baaˉ¹巴Mandarin Pinyin: zi4 da3 zui3 ba1
Meaning of 自打嘴巴
nounslap one's own face
noun自打耳光
nouncontradict oneself; self-contradictory; mutually exclusive
nounliterally: to slap one's own face; to contradict oneself