1448: nitpicking: What's a 'nit'? Nov 28, 2018

Chances are, most people don't know the name for a louse-egg, even though this is part of a phrase many might use daily. 'Nitpicking' is the process of being scrupulous about unimportant details, but very few people would know that a 'nit' is a louse-egg, and ridding oneself of these very tiny things—historically by hand—is 'nit-picking'. This just goes to show the way in which compounds like these—even though they have a very sensible summative meaning unlike 'butter-fly'—exist on their own, and not necessarily by mentally combining the elements.