It's called the repechage — pronounced rep-eh-shazh –— and it loosely translates in French to “to fish out” or “second chance." Track athletes competing in the following events now get an extra round –— if they need it — to reach their event's semifinals: men's and women's 200m, 400m, 800m, 1500m and hurdles events.
I had to look it up and show it to my husband cos he kept calling it "rickershaw" (but who am I kidding, he still won't pronounce it right). Only time I had ever heard the term used before was in sailing so I was surprised to hear it used here.