Petition to a deity (6)
I believe the answer is:
prayer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">petition to a deity</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for prayer that I've seen before include "Request (maybe to God)" , "Invocation, entreaty" , "Plea, invocation" , "Paternoster, for example" , "Request to deity" .)