1
general::
Phrase(s): split hairs
Fig. to quibble; to try to make petty distinctions. • They don’t have any serious differences. They are just splitting hairs. • Don’t waste time splitting hairs. Accept it the way it is.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Make trivial distinctions, quibble, as in Let's not split hairs about whose turn it is; I'll close up today and you do it tomorrow. This metaphoric idiom transfers dividing so fine an object as a single hair to other petty divisions. [Second half of 1600s]
American Heritage Idioms