A night(usually a Friday)when instead of going out and having a good time like most people your age, you spend the entire night on Tumblr. If you're a teenager this might start to worry your parents as it has mine.
Teen Boy: Hey are doing anything this Friday?

Teen Girl: No I'll probably just have another Tumblr night.
by PurplePaige64 August 28, 2010
Get the Tumblr night mug.