Provide professor with somewhere comfortable to sit (8)
I believe the answer is:
armchair
'somewhere comfortable to sit' is the definition.
(an armchair is a comfortable chair)
'provide professor' is the wordplay.
'provide' becomes 'arm' (arming is a kind of providing).
'professor' becomes 'chair' (chair can mean a professorship).
'arm'+'chair'='ARMCHAIR'
'with' acts as a link.
(Other definitions for armchair that I've seen before include "Roomy seat" , "Furniture item" , "Seat to relax in" , "Lacking practical expertise" , "Arch Irma perched on comfortable seat" .)