Sekha: a 'noble learner', a disciple in higher training, i.e. one who pursues the 3 kinds of training sikkhā, is one of those 7 kinds of Noble Disciples who have reached one of the 4 supra-mundane paths or the 3 lower fruitions see: ariya-puggala while the one possessed of the 4th fruition, or Arahatta-phala, is called 'one beyond training' asekha lit. 'no more learner'. The worldling puthujjana is called 'neither a noble learner, nor perfected in learning' n'eva-sekha-nāsekha Cf. Pug. 23-25.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.