Used to describe someone that looks like they have fell out of the ugly tree and hit every branch on the way down. Normally used on someone you see that you think is ugly and say oh my god she looks like dogsdinner.
Hey, John have you seen Trevors new girlfriend? Yeah, she looks like dogsdinner.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi