pupillage
Concise Oxford English Dictionary © 2008 Oxford University Press:
pupillage /ˈpjuːpɪlɪʤ/ (also pupilage)
▶noun
- 1 the state of being a pupil.
- 2 Law (in the UK) apprenticeship to a member of the Bar, which qualifies a barrister to practise independently.
'pupillage' also found in these Oxford entries:

