Well-thought-of agent joining university board (9)
I believe the answer is:
reputable
'well-thought-of' is the definition.
('reputable' can be similar in meaning to 'well-thought-of')
'agent joining university board' is the wordplay.
'agent' becomes 'rep' (short for representative).
'joining' says to put letters next to each other.
'university' becomes 'u'.
'board' becomes 'table' ('table' can be a synonym of 'board').
'rep'+'u'+'table'='REPUTABLE'
(Other definitions for reputable that I've seen before include "Regarded as fair" , "Trustworthy" , "of good name" , "Upright" , "Honest" .)