Stone mason turns up checking the last word (4)
I believe the answer is:
amen
'last word' is the definition.
(last word in a prayer)
'stone mason turns up checking' is the wordplay.
'checking' says the answer is hidden in the clue (I've seen 'checks' mean this (check can mean to curb or restrain)).
'turns up' says the letters should be written backwards.
'nema' is hidden within 'stone mason'.
'nema' backwards is 'AMEN'.
'the' acts as a link.
(Other definitions for amen that I've seen before include "Extremist" , "Word of agreement" , "I agree!" , "prayer's ending" , "Conclusion of prayer" .)