Open University book inspires college sequel (7)
I believe the answer is:
Here is my best explanation:
'sequel' is the definition.
'open university book inspires college' is the subsidiary indication.
'open university' becomes 'ou'.
'book' becomes 'tome' (a tome is a book**).
'inspires' means one lot of letters goes inside another (inspire means to breathe in).
'college' becomes 'c'.
'tome' enclosing 'c' is 'tcome'.
(Other definitions for outcome that I've seen before include "End result", "Cute moo (anag.)", "Eventuality", "Result or consequence", "'Result, upshot (7)'", "Consequence, effect", "Consequence, upshot", "answer", "Denouement" and "Consequence, result".)