noun
sophist; quibbler; person who argues with twisted logic
A derogatory term for someone who persistently uses far-fetched or hair-splitting arguments to avoid admitting they are wrong. Often implies stubbornness and a love of argument for its own sake.
彼は屁理屈屋で、何を言っても言い負かそうとする。
He's a quibbler who tries to argue you down no matter what you say.
あの屁理屈屋と議論しても時間の無駄だ。
Arguing with that sophist is a waste of time.
Compound of 屁理屈 (twisted logic, from 屁 'fart' + 理屈 'logic') and 屋 (suffix for a person with a certain trait). The exact historical derivation is uncertain, but the word is conventionally associated with the idea of using foul or nonsensical reasoning.