Ramble on about a repairman (7)
I believe the answer is:
meander
'ramble' is the definition.
(thesaurus)
'about a repairman' is the wordplay.
'about' is an insertion indicator.
'repairman' becomes 'mender' (mender is a kind of repairman).
'a' placed into 'mender' is 'MEANDER'.
'on' is the link.
(Other definitions for meander that I've seen before include "Roam aimlessly around" , "Renamed in order to wander in leisurely way" , "Renamed (anag)" , "Zigzag" , "Red mane (anag) - roam aimlessly" .)