O level

сокращение от Ordinary Level; то же, что и O level

Большой англо-русский словарь

O level

noun 1. the lowest of three levels of standardized British examinations in a secondary school subject; also successful completion of an O-level examination in a particular subject — called also Ordinary level — compare A level, S level 2. a. the level of education required to pass an O-level examination b. a course leading to an O-level examination

Merriam-Webster's Collegiate Dictionary