The act of embarking on an endeavour so titanically stupid and damaging, that your
peer-group will hate you forever.
For extra effect, a "full sunak" should begin with announcing your intent in the most embarassing situation possible (eg on national
TV, while standing in the torrential
rain without an umbrella)
We were on this road trip with Carl, and his car caught
fire. Turns out that when he was joking about having poured petrol everywhere, he wasn't joking. The whole
thing was a
proper full-sunak