Merriam-Webster Collegiate Dictionary - a level

 noun  Date: 1951  1. the second of three standardized British examinations in a secondary school subject used as a qualification for university entrance; also successful completion of an A-level examination in a particular subject — called also Advanced level — compare O level, S level  2.  a. the level of education required to pass an A-level examination  b. a course leading to an A-level examination