1. argue about or focus on the trivial aspects of something
let's not split hairs
When someone accuses you of 'splitting hairs' it means to spend time worrying about small details or little distinctions that don't have any importance. In a literal sense, not only would it be very difficult to actually split a hair, but it would also be a totally pointless act. This expression refers to pointlessly arguing about or focusing on trivial differences or unimportant details. 'Splitting hairs' is often associated with being petty or overly pedantic and is commonly used in both a social and professional context. A term with a similar meaning is 'to nitpick.'