Snick a ____

Perhaps someone who's a professional crossword constructor is lurking out there reading my friends list, so I'll go ahead and ask here. Some day I may remember to ask Will Shortz.

Why the hell is SNEE often defined as a "Dundee dagger" (or Scottish dagger, or the like)? I cannot find any connection to Scotland at all. If anything, the word is Dutch. I feel like someone must've defined it that way once, and it went into everyone's databases, and no one ever really checked it.

Anyone? Anyone? (Have I asked this here before?)