Plain English Meaning
A pilot who is licensed to fly small, simple aircraft in good weather during the day, with one passenger at most. It is the entry-level FAA pilot certificate and has the fewest training hours required.
Full Definition
A sport pilot is the holder of a sport pilot certificate, an FAA pilot certificate that authorizes flight only in light-sport aircraft (LSA) under specific limitations: daytime only, visual flight rules, no flight above 10,000 feet MSL, no flight in Class A airspace, and carrying no more than one passenger. A sport pilot may use a current and valid U.S. driver's license in place of an FAA , provided has not had their most recent medical denied, suspended, or revoked.