noun
quibble; pointless argument; sophistry
Refers to nitpicking, hair-splitting, or arguing over trivial logical points. Often used dismissively.
彼はいつも小理屈を言って議論を長引かせる。
He always drags out discussions by making quibbles.
そんな小理屈はやめて、本題に入ろう。
Stop that pointless arguing and let's get to the main topic.
Compound of 小 (small, petty) and 理屈 (logic, reasoning). The exact historical derivation is uncertain, but the word transparently means 'petty logic'.