Wise to join fellow minister (10)
I believe the answer is:
politician
'minister' is the definition.
(thesaurus)
'wise to join fellow' is the wordplay.
'wise' becomes 'politic' (associated in meaning).
'to join' says to put letters next to each other.
'fellow' becomes 'ian' (common masculine name).
'politic'+'ian'='POLITICIAN'
(Other definitions for politician that I've seen before include "Legislator" , "Eg, an MP" , "US senator?" , "could be Congressman" , "One in Westminster" .)