1. The number underneath in a fraction after simplification
2. A dumbass or a group of dumbasses
1. "I got half marks in that maths test because I didn't simplify to the lowest common denominator"
2. "I got into a fight with a group of the lowest common denominator, mate"
Downloading many, many albums, movies etc. when you realise it's the end of the month and you want your month's worth of downloading. Usually done so the rest of the month has Broadband-speed internet.
"Any albums you want while I'm binge downloading?"