Sphere of activity involving students’ literary output? (8)

I believe the answer is:

universe

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'sphere of activity' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for universe that I've seen before include "all we know?" , "Everything that exists anywhere" , "mind-boggling concept" , "Cosmos" , "The whole of creation" .)

I've seen this clue in The Times.

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