You look down during the day to notice your member sitting larger than usual (n.b. refers to a larger than average floppy length and/or girth). CONGRATULATIONS - you are having a big dick day!
A smiling Jim emerges from the bushes having taken a quick whizz. "Great news... I'm having a big dick day" says Jim to his friends. Friends are happy for Jim (some high five).
by Ben UK 2010 June 12, 2010
Get a Big Dick Day mug for your boyfriend Jerry.
When you organise a spectacular military parade to say, "Tanks" to all your dictator friends.
Did you see all those Russian tanks at the inaugural Big Dick Day?
by No Hemingway July 03, 2019
Get a Big Dick Day mug for your cousin Trump.
November 13th. A day for all of the gents to celebrate their endowment. The first National Big Dick Day was started in 1798 by John "Big J" Dickinson, with the date chosen to be his birthday. The validity of Big J's claims is disputed.
Matt: "How did you celebrate National Big Dick Day?"

Nate: "Not allowed to."

Matt: "Damn."
by Billiam27 June 04, 2021
Get the National Big Dick Day neck gaiter and mug.
May 26 every one born on this day has a big dick
I'm reddy or big dick day
by its big boy November 08, 2019
Get a big dick day mug for your buddy Nathalie.