To fire one off is to take a crap.
I hadn't crapped for a month, until I couldn't hold it in any longer and I then just fired one off.
by OliverS May 07, 2005
Get a fire one off mug for your dog Vivek.
My bitch wasn't around and I was hornier than a dog with two dicks, so I quickly fired one off the cuff before she came home.
by Absintheminded April 09, 2004
Get a fire one off the cuff mug for your mama Julia.