Definition of "showstopping"

“You look absolutely showstopping. I hope you know that.” “Showstopping, is it? That's a new one.”

2014, J. P. Francis, The Major's Daughter‎, Penguin

14 Showstopping Desserts That Don’t Require a Mixer [title]

2021 October 20, Nikita Richardson, “14 Showstopping Desserts That Don’t Require a Mixer”, in The New York Times‎

There is a school of thought that says you should periodically fix these issues ahead of the showstopping bugs.

2016, Steven Goodwin, Polished Game Development: From First Steps to Final Release, Apress, page 186