Term used when something is not going the way in which it was intended. Such as a bad day at work or when something has gone awry. In a really bad situation, "Huge Freakin' Boner" can be used.
Guy 1- Hey Ryan how's that job going today? Guy 2- Well Ray, I just found out this 8 hour job is going to take atleast 12 hours and I have to do all this extra stuff, I got a Huge Boner right now.