Plain English Meaning
It is the final test where an examiner checks both what you know and how you fly. You sit down for questions first, then go fly the airplane while being graded. Pass it, and you earn the certificate or rating you have been training for.
Full Definition
The check ride is the practical test administered by an FAA-designated examiner that a pilot must pass to be issued a pilot certificate or rating. It consists of an oral examination on aeronautical knowledge followed by an in-flight evaluation of flying skill, judgment, and decision-making against the standards published in the applicable Airman Certification Standards (ACS) or Practical Test Standards ().