Used to describe an erection so hard that even a dingo (Australia's native wild dog) couldn't damage it.

Given the silliness of the expression, it's usually used to describe extreme enjoyment of an activity not related to sex, such as a sporting triumph.
When the Cats won the 2007 AFL Grand Final, I had a boner a dingo couldn't bite through for the next week.
by Choda Boy 57 May 9, 2008
Get the boner a dingo couldn't bite through mug.