A code probably once served a purpose, but doesn't anymore. You're afraid of removing it because after years it just looks right the way it is.
In evolutionary biology vestigial organs are the ones an organism probably once used but no longer serve a purpose today.
yungsnuggie almost 5 years ago James: Dude help me debug my new one button app, "Dude."
Zeeshan: What is all this? None of it serves a purpose.
James: It's vestigial code that makes gives me confidence when making something new. I've just built everything on top of my dayspan code from freshman year until now. I commented it out, don't worry.
Zeeshan: You're a terrible human being, you know that?
James: Dude help me debug my new one button app, "Dude."