Part of prayer? Yes (3)
I believe the answer is:
aye
'yes' is the definition.
(thesaurus)
'part of prayer?' is the wordplay.
'part of' says the answer is hidden in the clue.
'AYE' can be found hidden inside 'prayer'.
(Other definitions for aye that I've seen before include "Word of assent" , "Affirmative answer" , "An affirmative vote" , "Always" , "Indeed" .)