pooh-pooh (v.)youdaoicibaDictYouDict[pooh-pooh 词源字典]
"to dismiss lightly and contemptuously," 1827, a slang reduplication of dismissive expression pooh. Among the many 19th century theories of the origin of language was the Pooh-pooh theory (1860), which held that language grew from natural expressions of surprise, joy, pain, or grief.[pooh-pooh etymology, pooh-pooh origin, 英语词源]