Conclusion of prayer for first-rate people (4)
I believe the answer is:
amen
'conclusion of prayer' is the definition.
(I've seen this before)
'first-rate people' is the wordplay.
'first-rate' becomes 'A'.
'people' becomes 'men' (men are people).
'a'+'men'='AMEN'
'for' is the link.
(Other definitions for amen that I've seen before include "I agree!" , "prayer's ending" , "Religiously 11 [THE LASTWORD]" , "Last word of prayer" , "Approve" .)