noun
sophistry; specious argument; quibbling
Refers to arguments that are logically twisted, far-fetched, or made just for the sake of arguing, often ignoring common sense. Commonly used in the phrase 屁理屈をこねる (to quibble or split hairs).
彼はいつも屁理屈ばかり言って、話が進まない。
He always spouts sophistry and the conversation never moves forward.
そんな屁
That kind of quibbling won't work.
理屈 means 'logic' or 'reasoning' in a neutral sense; 屁理屈 adds the derogatory prefix 屁 (flatulence) to imply twisted or worthless logic.
Compound of 屁 (he, 'fart') and 理屈 (rikutsu, 'logic, reasoning'), literally 'fart logic', implying worthless or twisted reasoning. The exact origin is uncertain, but it is a colloquial coinage.