A fellow fairly contained, don't forget (5,2)
I believe the answer is:
dwell on
'don't forget' is the definition.
I can't tell whether this defines the answer.
'a fellow fairly contained' is the wordplay.
'a fellow' becomes 'don' (both can mean an academic).
'fairly' becomes 'well' (I can't explain this - if you can you should believe this answer much more).
'contained' is an insertion indicator.
'don' going around 'well' is 'DWELL ON'.
Can you help me to learn more?
(Other definitions for dwell on that I've seen before include "Speak at length about" , "Think at length about" , "Linger over" , "Mull over" , "Ponder about" .)