What can a "rolling correction" mean, other than the let's say scientific meaning of correcting the rolling trajectory of a certain object.
See, e.g. CNBC:
Boockvar said Wednesday's dramatic snap back in the market did not dissuade him from his view. "We've had a rolling correction. We're going to have buyers on the dip, as we did today, but I'm not changing my opinion that going into September, there's a very high chance of a correction," he said. The Dow was down more than 275 points Wednesday morning and ended the day just 40 points lower.