A sweater of no/or little value often torn or missing specific lettering/logos/tags that any normal sweater might of once had.
I ran out of laundry so I wore my ugly sweater.
Ugly Sweater: define #2
When you are really excited to have sex with a guy for the first time. He’s highly attractive and once you unwrap his package it is disappointing, like an ugly sweater from your aunt.
Oh man I was so pumped to fuck that guy, but once we got down to it, he was a total ugly sweater. I just wanted to wrap it back and return it.