In which to start work (or play) (8)
I believe the answer is:
openings
'work or play' is the definition.
I can't tell whether this defines the answer.
'in which to start' is the wordplay.
'in which' becomes 'ings' (I am not sure about this - if you are sure you should believe this answer much more).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'start' becomes 'open' (opening is a kind of starting).
'ings' put after 'open' is 'OPENINGS'.
Can you help me to learn more?
(Other definitions for openings that I've seen before include "Opportunities, for employment say" , "Gaps or beginnings" , "Job opportunities or apertures" , "Holes or opportunities" , "Apertures or job vacancies" .)