Reproductive organ displayed by holy man having the last word (6)
I believe the answer is:
stamen
'reproductive organ' is the definition.
(I've seen this before)
'displayed by holy man having the last word' is the wordplay.
'displayed by' means one lot of letters go next to another.
'holy man' becomes 'st'.
'having the last word' becomes 'amen' (I've seen this before).
'st'+'amen' is 'STAMEN'.
(Other definitions for stamen that I've seen before include "Flower's pollen carrier" , "Male ditto" , "Bit of a bloomer" , "The pollen-bearing organ of flowering plants" , "Pollen producer" .)