Definition of hair-splitting in English English dictionary
the act of finding exceedingly small differences which are probably neither important nor noticeable to most people
Dick's Tribune poked endless fun at the hair-splitting sectarianism of the various Trotskyist groups jostling on the fringes of the Labour party at that time.
when people pay too much attention to small differences and unimportant details, especially in an argument split hairs split (8)