Beam in for every petition (6)
I believe the answer is:
prayer
'petition' is the definition.
(synonyms)
'beam in for every' is the wordplay.
'beam' becomes 'ray' (synonyms).
'in for' is an insertion indicator.
'every' becomes 'per' ('per' means 'for each' or 'for every').
'ray' going inside 'per' is 'PRAYER'.
(Other definitions for prayer that I've seen before include "Reverent petition to a deity" , "Maybe collect" , "Earnest hope" , "Orison" , "Paternoster, for example" .)