I remember some time back coming across something that said something like "The term 'daddy long-legs' properly refers to the Opiliones or harvestman, but some people apply it to the crane-fly"

And I was like (A) What the heck, man, you do not get to declare that one colloquial regionalism is more proper than another, and (B) neither of these creatures is the daddy long-legs I grew up with (the Pholcus or cellar spider, which is imo much more deserving of the title than the harvestman)