Standing joke ultimately on ecclesiastic, or not (5)
I believe the answer is:
erect
'standing' is the definition.
(similar in meaning)
'joke ultimately on ecclesiastic or not' is the wordplay.
'joke ultimately' becomes 'e' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'on' is a charade indicator (letters next to each other).
'ecclesiastic' becomes 'rector' (ecclesiastic can mean a priest).
'not' indicates named letters should be taken away.
'rector' with 'or' removed is 'rect'.
'e'+'rect'='ERECT'
(Other definitions for erect that I've seen before include "Upright; construct" , "Standing straight" , "Crete (anag)" , "Build, put up" , "Assemble" .)